The Dr.pen Microneedling System is a microneedling device and accessories intended to be used as a treatment to improve the appearance of facial acne scars in adults aged 22 years and older.

Device Description

The Dr.pen Microneedling System is a minimally invasive microneedling device that mechanically creates microscopic punctures in the epidermal and dermal layers of the skin by means of micro-needles in a reciprocating cartridge head. The Dr. pen Microneedling System is comprised of a reusable pen body, a sterile, single use microneedling cartridge, a power adapter, and a disposible protective sleeve. The microneedling cartridge is attached to the pen body and activated with an On/Off button. The depth of needle penetration can be adjusted by the user depending on the condition of the skin being treated. Charging is accomplished by attaching the Dr.pen pen body to the power adapter.

AI/ML Overview

The provided document is a 510(k) premarket notification for a microneedling device. It focuses on demonstrating substantial equivalence to a previously cleared predicate device, not on proving de novo performance criteria for a novel device. Therefore, the information typically associated with acceptance criteria and a detailed study proving performance against those criteria (especially regarding AI/human reader studies, ground truth, and sample sizes for training/test sets) is not present in this document.

The document primarily discusses bench testing to show that the device meets safety and performance standards equivalent to the predicate device, not a clinical study to prove efficacy in improving acne scars based on image analysis or similar AI-assisted diagnostics.

Here's a breakdown of what can be extracted and what information is missing based on your request:

Information Present in the Document:

Acceptance Criteria and Device Performance (in a limited sense related to substantial equivalence):
The document focuses on comparing technological characteristics to a predicate device and demonstrating equivalence through bench testing. It does not provide a table of acceptance criteria for diagnostic performance (e.g., sensitivity, specificity, accuracy) because it's a microneedling device for aesthetic use, not an AI diagnostic tool.

The "acceptance criteria" here are implied by the standards and bench tests performed to show equivalence in physical and electrical characteristics and safety.

Acceptance Criteria (Implied by Bench Testing & Predicate Equivalence)	Reported Device Performance (Dr.pen Microneedling System)
Motor Speed Puncture Rate: Match predicate range (6300-7700 RPM, 105-128 stamps/sec)	Reported as "Same" as predicate (6300-7700 RPM, 105-128 stamps/second)
Needle Penetration Depth and Extension Accuracy: Accurate to selected depth settings and within acceptable tolerances	Bench testing performed; results supported substantial equivalence. Specific accuracy values not listed.
Needle Bonding Strength: Sufficient for intended use	Bench testing performed; results supported substantial equivalence. Specific strength values not listed.
Use Life Testing: Device maintains function over expected lifespan	Bench testing performed; results supported substantial equivalence. Specific lifespan not listed.
Cartridge Life Testing: Cartridge maintains function over expected lifespan	Bench testing performed; results supported substantial equivalence. Specific lifespan not listed.
Anti-suction Testing: Prevent suction/tissue damage	Bench testing performed; results supported substantial equivalence.
Microbial Ingress Testing: Prevent microbial contamination	Bench testing performed; results supported substantial equivalence.
Cleaning and Disinfection Validation: Effective cleaning and disinfection	Passed ISO 11737-1, AAMI TIR-30, AAMI TIR-12.
Sterilization and Shelf Life: Maintain sterility and integrity for specified shelf life	Passed ISO 11135-2014, ISO 11737-1:2018, ISO 11737-2:2009, ISO 10993-7:2008, ASTM F1980-16, ASTM F1886/F1886M-16, ASTM F1929-2015, ASTM F88/F88M-2015, ASTM D3078-02(2013), ASTM F1140-2013, DIN 58953-6:2016, ISO 11737-2:2019.
Biocompatibility: Non-toxic, non-sensitizing, non-irritating, non-pyrogenic	Passed Cytotoxicity (ISO 10993-5:2009), Sensitization/Irritation/Intracutaneous Reactivity (ISO 10993-10:2010), Acute Systemic Toxicity (ISO 10993-11:2017), Material Mediated Pyrogenicity (ISO 10993-11:2017, USP 41 NF 36:2018, <151> Pyrogen Test). "Demonstrated the device to be biocompatible with no evidence of material mediated pyrogenicity."
Electrical Safety and EMC: Compliance with medical electrical safety standards	Passed IEC 60601-1:2005 + A1:2012 and EN/IEC 60601-1-2:2015 /IEC 60601-1-2:2014.

Sample Size used for the test set and data provenance:
- Sample Size: Not applicable in the context of human clinical data for a "test set" as understood for AI performance. The "testing" here refers to bench testing of the device's physical/electrical properties. No patient data or image data test sets are mentioned.
- Data Provenance: Not applicable. The testing is bench-based, not clinical or image-based.
Number of experts used to establish ground truth for the test set and qualifications:
- Not applicable. This device is not an AI diagnostic tool that requires expert ground truth establishment for a test set.
Adjudication method for the test set:
- Not applicable.
If a multi-reader multi-case (MRMC) comparative effectiveness study was done:
- No. This type of study is typically done for diagnostic imaging AI devices to compare human performance with and without AI assistance. This document is for a physical microneedling device.
If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
- Not applicable. This device does not have a standalone "algorithm only" performance that would be evaluated in this manner.
The type of ground truth used:
- Not applicable. For the bench testing, the "ground truth" would be the established engineering/materials standards and specifications.
The sample size for the training set:
- Not applicable. This is not an AI/machine learning device that would have a "training set."
How the ground truth for the training set was established:
- Not applicable.

Summary Conclusion:

The provided FDA 510(k) clearance letter and summary for the "Dr.pen Microneedling System" is for a physical medical device (a microneedling device). It is not for an AI-powered diagnostic or assistive tool. As such, the information requested regarding AI acceptance criteria, clinical test sets, expert ground truth, MRMC studies, training data, etc., is not relevant or present in this type of regulatory submission. The regulatory pathway followed here relies on demonstrating substantial equivalence to an existing predicate device through bench testing for safety and performance characteristics, not through clinical efficacy studies involving AI performance metrics.

Summary

{0}------------------------------------------------

Image /page/0/Picture/0 description: The image shows the logo of the U.S. Food and Drug Administration (FDA). The logo consists of two parts: the Department of Health & Human Services logo on the left and the FDA logo on the right. The FDA logo is in blue and includes the letters "FDA" followed by the words "U.S. Food & Drug Administration".

August 11, 2023

Guangzhou Ekai Electronic Technology Co., Ltd. % Helen Nan General Manager New Risen Enterprise Management Consulting Co., Ltd. Room 302, Building 3, Hangqian Mansion Hangqian Street, Lucheng District Wenzhou. Zhejiang 325000 China

Re: K230420

Trade/Device Name: Dr. pen Microneedling System Regulation Number: 21 CFR 878.4430 Regulation Name: Microneedling Device For Aesthetic Use Regulatory Class: Class II Product Code: OAI Dated: July 14, 2023 Received: July 14, 2023

Dear Helen Nan:

We have reviewed your Section 510(k) premarket notification of intent to market the device referenced above and have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food, Drug, and Cosmetic Act (Act) that do not require approval of a premarket approval application (PMA). You may, therefore, market the device, subject to the general controls provisions of the Act. Although this letter refers to your product as a device, please be aware that some cleared products may instead be combination products. The 510(k) Premarket Notification Database located at https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpmn/pmn.cfm identifies combination product submissions. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration. Please note: CDRH does not evaluate information related to contract liability warranties. We remind you, however, that device labeling must be truthful and not misleading.

If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 898. In addition, FDA may publish further announcements concerning your device in the Federal Register.

Please be advised that FDA's issuance of a substantial equivalence determination does not mean that FDA has made a determination that your device complies with other requirements of the Act or any Federal

{1}------------------------------------------------

statutes and regulations administered by other Federal agencies. You must comply with all the Act's requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Part 801); medical device reporting of medical device-related adverse events) (21 CFR 803) for devices or postmarketing safety reporting (21 CFR 4, Subpart B) for combination products (see https://www.fda.gov/combination-products/guidance-regulatory-information/postmarketing-safety-reportingcombination-products); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820) for devices or current good manufacturing practices (21 CFR 4, Subpart A) for combination products; and, if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.

Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR Part 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to https://www.fda.gov/medical-device-safety/medical-device-reportingmdr-how-report-medical-device-problems.

For comprehensive regulatory information about medical devices and radiation-emitting products, including information about labeling regulations, please see Device Advice (https://www.fda.gov/medicaldevices/device-advice-comprehensive-regulatory-assistance) and CDRH Learn (https://www.fda.gov/training-and-continuing-education/cdrh-learn). Additionally, you may contact the Division of Industry and Consumer Education (DICE) to ask a question about a specific regulatory topic. See the DICE website (https://www.fda.gov/medical-device-advice-comprehensive-regulatoryassistance/contact-us-division-industry-and-consumer-education-dice) for more information or contact DICE by email (DICE@fda.hhs.gov) or phone (1-800-638-2041 or 301-796-7100).

Sincerely, Digitally signed Mark by Mark Trumbore Trumbore - S Date: 2023.08.11 -5 08:02:17 -04'00' Mark Trumbore, Ph.D. Assistant Director DHT4A: Division of General Surgery Devices OHT4: Office of Surgical and Infection Control Devices Office of Product Evaluation and Ouality Center for Devices and Radiological Health

Enclosure

{2}------------------------------------------------

Indications for Use

510(k) Number (if known) K230420

Device Name Dr.pen Microneedling System

Indications for Use (Describe)

The Dr.pen Microneedling System is a microneedling device and accessories intended to be used as a treatment to improve the appearance of facial acne scars in adults aged 22 years and older.

Type of Use (Select one or both, as applicable)

	Prescription Use (Part 21 CFR 801 Subpart D)
	Over-The-Counter Use (21 CFR 801 Subpart C)

CONTINUE ON A SEPARATE PAGE IF NEEDED.

This section applies only to requirements of the Paperwork Reduction Act of 1995.

DO NOT SEND YOUR COMPLETED FORM TO THE PRA STAFF EMAIL ADDRESS BELOW.

The burden time for this collection of information is estimated to average 79 hours per response, including the time to review instructions, search existing data sources, gather and maintain the data needed and complete and review the collection of information. Send comments regarding this burden estimate or any other aspect of this information collection, including suggestions for reducing this burden, to:

Department of Health and Human Services Food and Drug Administration Office of Chief Information Officer Paperwork Reduction Act (PRA) Staff PRAStaff(@fda.hhs.gov

"An agency may not conduct or sponsor, and a person is not required to respond to, a collection of information unless it displays a currently valid OMB number."

{3}------------------------------------------------

Image /page/3/Picture/1 description: The image contains the logo for Guangzhou Ekai Electronic Technology Co., Ltd. The logo features a blue crescent shape on the left, followed by a square containing the text "Ekai" and smaller text "意机科技". To the right of this is the company name in Chinese characters, followed by the English translation "Guangzhou Ekai Electronic Technology Co., Ltd."

K230420_510(k) Summary (As required by 21 CFR 807.92(a))

1.0 Submitter Information

Company:	Guangzhou Ekai Electronic Technology Co.,Ltd.
Address:	Third Floor, Building E, No.81 Zijing Road, LiwanDistrict, Guangzhou, Guangdong, CHINA
Phone:	+86-20-81177539
Contact Person:	Guihua Chen
Title:	CEO
Summary Prepared Date:	July 14th, 2023

2.0 Device Information

Trade/Device Name:	Dr.pen Microneedling System
Model:	A20
Device:	Powered Microneedle Device
Regulation Description:	Microneedling device for aesthetic use
Product Code:	QAI
Review Panel:	General & Plastic Surgery
Submission Type:	510(k)
Regulation Number:	CFR 878.4430
Device Class:	Class II

3.0 Predicate Device and Reference Device Information

Predicate Device:
Trade/Device Name:	SkinPen® Precision System
K Number:	DEN160029
Submitter:	Bellus Medical, LLC
Reference Device:
Trade/Device Name:	MicroPen EVO™
K Number:	K203144
Submitter:	Eclipse MedCorp, LLC

4.0 Device Description

{4}------------------------------------------------

Image /page/4/Picture/1 description: The image contains the logo for Guangzhou Ekai Electronic Technology Co., Ltd. The logo features a blue crescent shape on the left, followed by the company name in both Chinese and English. The Chinese name is "广州意凯电子科技有限公司", and the English name is "Guangzhou Ekai Electronic Technology Co., Ltd.". There is also a smaller square logo with the text "Ekai" and "意机科技".

5.0 Indications for Use

The Dr.pen Microneedling System is a microneedling device and accessories intended to be used as a treatment to improve the appearance of facial acne scars in adults aged 22 years and older.

{5}------------------------------------------------

Image /page/5/Picture/1 description: The image contains the logo for Guangzhou Ekai Electronic Technology Co., Ltd. The logo features a stylized letter "C" shape in blue, with a square containing the text "Ekai" in orange. The full company name is written in both Chinese and English next to the logo. The English translation is "Guangzhou Ekai Electronic Technology Co., Ltd."

6.0 Comparison of Technological Characteristics with the Predicate Device

The Dr.pen Microneedling System has the identions for use as the predicate device and the same or equivalent technological features. A comparison of the subject and predicate device's technological features is presented in the following table.

Property	Predicate Device	Reference Device	Subject Device	Comparison
Device Name	SkinPen® Precision System	MicroPen EVO™	Dr.pen Microneedling System	-
510(K) Number	DEN160029	K203144	K230420	-
Classification name	Microneedling device foraesthetic use	Microneedling device foraesthetic use	Microneedling device foraesthetic use	Same
Product Code	QAI	QAI	QAI	Same
Classification	Class II	Class II	Class II	Same
Regulation Number	21 CFR 878.4430	21 CFR 878.4430	21 CFR 878.4430	Same
Use	Prescription use	Prescription use	Prescription use	Same
Indications For Use	SkinPen® Precision System is amicroneedlingdeviceandaccessories intended to be usedas a treatment to improve theappearance of facial acne scars inadults aged 22 years or older.	The Eclipse MicroPen EVO is amicroneedlingdeviceandaccessories intended to be usedas a treatment to improve theappearance of facial acne scars inadults aged 22 years and older.	The Dr.pen MicroneedlingSystem is a microneedling deviceand accessories intended to beused as a treatment to improvethe appearance of facial acnescars in adults aged 22 years orolder.	Same
Intended Locationof Use	Face	Face	Face	Same
Power Source(Pen Body)	Rechargeable Li-ion battery	Rechargeable Li-ion battery	Rechargeable Li-ion battery	Same
Power Source(Battery Charger)	AC Powered	AC Powered	AC Powered	Same
ControlMechanism	Microprocessor;embedded software	Microprocessor;embedded software	Microprocessor;embedded software	Same
Single Speed(RPM)	6300 - 7700	6300 - 7700	6300 - 7700	Same
Puncture Rate	105 -128 stamps/second	105 -128 stamps/second	105 -128 stamps/second	Same
MicroneedlingCartridge	Sterile, Single Use	Sterile, Single Use	Sterile, Single Use	Same
No. of Needles	14	14	14	Same
Needle Gauge	34 Ga	34 Ga	34 Ga	Same
Needle Material	Stainless Steel	Stainless Steel	Stainless Steel	Same
Needle ShapeGeometry	Straight, cylindrical body with aconical tapered, sharp point	Straight, cylindrical body with aconical tapered, sharp point	Straight, cylindrical body with aconical tapered, sharp point	Same
Arrangement	Needles radially arranged	Needles radially arranged	Needles radially arranged	Discussion¹
Needle Spacing	2 mm spacing/3.54 mm² perneedle	2 mm spacing/3.48 mm² perneedle	2 mm spacing/3.96 mm² perneedle	Discussion²
Penetration Depth	1.5 mm(Recommended)	1.5 mm(Recommended)	1.5 mm(Recommended)	Same
Max. NeedleDepth Setting	2.5 mm	2.00 mm	2.0 mm	Discussion³
PenetrationDepth Selection	11 depth settings; 0 mm to 2.5mm in 0.25 mm increments	9 depth settings; 0 mm to 2.0 mmin 0.25 mm increments	9 depth settings; 0 mm to 2.0 mmin 0.25 mm increments	Same
Sterility (cartridge)	Ethylene Oxide	Ethylene Oxide	Ethylene Oxide	Same
Shelf Life (cartridge)	2 years	2 years	2 years	Same
Barrier: Cross/Contamination	BioSheath(Disposable)	MicroSleeve Sheath(Disposable)	Protective Sleeve(Disposable)	Same

{6}------------------------------------------------

Image /page/6/Picture/1 description: The image shows the logo for Guangzhou Ekai Electronic Technology Co., Ltd. The logo features a blue arc on the left side, followed by a square containing the word "Ekai" in orange. To the right of the square, the company name is written in both Chinese and English. The English translation reads "Guangzhou Ekai Electronic Technology Co., Ltd."

{7}------------------------------------------------

Discussion': the reference device (Eclipse MicroPen EVO, K203114) has included to support that the subject device is the same as the reference device and state substantial equivalence to the a legally marketed device.

Discussion2: subject device has a slightly larger total surface area of the hub. No affect to geometry, puncture pattern, needle stamp.

Discussion3: not significant difference; treatment depth is 1.5 mm for both devices.

Substantial Equivalence:

Dr.pen Microneedling System is substantially equivalent to the Bellus Medical SkinPer® Precision System predicate device. The devices are under the same product code (QAI), both have the same indication for use, same number of needles, gauge, shape and arrangement, same material, recommended peneth, speed, puncture rate and sterilization method. The only technological differences are the maximum needle depth setting: the Dr.pen is 0.5 mm than the predicate (2.5 mm); and the penetration depth selection: the Dr.pen has 9 depth settings (0-2.0 mm increments) and the predicate device has 11 depth settings (0-2.5 mm in 0.25 mm increments). These differences are minor and are not significant since both devices recommend the same treatment depth (1.5 mm). There is a small and insignificant difference between the surface area of the hub, however the needle spacing is the same (2 mm) and there is no effect on geometry, puncture pattern, These minor differences do not raise different questions of safety and effectiveness. Further, the results of performance testing support substantial equivalence of the Dr.per on to the predicate device.

{8}------------------------------------------------

Image /page/8/Picture/1 description: The image shows the logo for Guangzhou Ekai Electronic Technology Co., Ltd. The logo consists of a blue crescent shape on the left, followed by the company name in both English and Chinese. The English name is "Guangzhou Ekai Electronic Technology Co., Ltd." and the Chinese name is "广州意凯电子科技有限公司". There is also a square logo with the word "Ekai" in it.

7.0 Performance Testing-Bench

In combination with the general controls of the FD&C Act, the Dr.pen Microneedling System for aesthetic use has been subjected to performance testing and adheres to the following special controls and standards:

7.1 Bench Testing

A Motor Speed Puncture Rate Testing
Needle Penetration Depth and Extension Accuracy Testing A
Needle Bonding Strength Test
A Use Life Testing
A Cartridge Life Testing
A Anti-suction Testing
A Microbial Ingress Testing

7.2 Cleaning and Disinfection Validation

ISO 11737-1: 2018 (AAMI TIR-30; 2011; AAMI TIR-12:2004) Cleaning A Validation Intermediate-Level Disinfection Validation

7.3 Sterilization and Shelf Life

Ethylene oxide sterilization per ISO 11135-2014; ISO11737-1:2018; ISO A 11737-2: 2009; ISO 10993-7:2008
A Sterilization, Shelf Life/Package Integrity in accordance with the following standards:
- · Standard Guide for Accelerated Aging of Sterile Barrier Systems for Medical Devices medical devices ASTMF1980-16
- · Standard Test Method for Determining Integrity of Seals for Flexible Packaging by Visual Inspection ASTM F1886/F1886M-16
- · Standard Test Method for Detecting Seal Leaks in Porous Medical Packaging by Dye Penetration ASTM F1929-2015
- · Standard Test Method for Stripping Strength of Flexible Sealing Materials ASTM F88/F88M-2015
- · Standard Test Method for Determination of Leaks in Flexible Packaging by Bubble Emission ASTM D3078-02(2013)
- · Standard Test Methods For Internal Pressurization Failure Resistance Of Unrestrained Packages ASTM F1140-2013
- · Sterilization Sterile supply Part 6: Microbial barrier testing of packaging materials for medical devices which are to be sterilized DIN 58953-6:2016
- · Sterilization of medical devices Microbiological methods Part 2: Tests of sterility performed in the definition, validation and maintenance of a sterilization process ISO 11737-2: 2019

8.0 Biocompatibilitv

The following tests were performed on the final, finished microneedling cartridge: Cytotoxicity (ISO 10993-5:2009); A

{9}------------------------------------------------

Image /page/9/Picture/1 description: The image shows a logo with a blue partial circle on the left side. Inside the circle is an orange square with the word "Ekai" written in black on the right side of the square. Below "Ekai" are two Chinese characters in black.

州意凯电子科技有限公

Sensitization and Irritation/Intracutaneous Reactivity (ISO 10993-10: 2010);
Acute Systemic Toxicity (ISO 10993-11:2017);
Material Mediated Pyrogenicity (ISO 10993-11:2017, USP 41 NF 36:2018, <151> Pyrogen Test).

The results of these tests demonstrated the device to be biocompatible with no evidence of material mediated pyrogenicity.

10.0 Electrical Safety and Electromagnetic Compatibility

A IEC- 60601-1:2005 + A1: 2012 – Medical electrical equipment-Part 1: General Requirements for Basic Safety and Essential Performance;
EN/IEC 60601-1-2: 2015 /IEC 60601-1-2: 2014-Medical electrical equipment-Part 1-2: General requirements for basic safety and essential performance - Collateral standard: Electromagnetic compatibility - Requirement and tests.

11.0 Statement of Substantial Equivalence

The results of the performance testing described above demonstrate that Dr.pen Microneedling System is as safe and effective as SkinPen® Precision System [510K Number: DEN160029; submitted by Bellus Medical, LLC] supports a determination of substantial equivalence.

Regulation Number and Section

§ 878.4430 Microneedling device for aesthetic use.

(a)
Identification. A microneedling device for aesthetic use is a device using one or more needles to mechanically puncture and injure skin tissue for aesthetic use. This classification does not include devices intended for transdermal delivery of topical products such as cosmetics, drugs, or biologics.(b)
Classification. Class II (special controls). The special controls for this device are:(1) The technical specifications and needle characteristics must be identified, including needle length, geometry, maximum penetration depth, and puncture rate.
(2) Non-clinical performance data must demonstrate that the device performs as intended under anticipated conditions of use. The following performance characteristics must be tested:
(i) Accuracy of needle penetration depth and puncture rate;
(ii) Safety features built into the device to protect against cross-contamination, including fluid ingress protection; and
(iii) Identification of the maximum safe needle penetration depth for the device for the labeled indications for use.
(3) Performance data must demonstrate the sterility of the patient-contacting components of the device.
(4) Performance data must support the shelf life of the device by demonstrating continued sterility, package integrity, and device functionality over the intended shelf life.
(5) Performance data must demonstrate the electrical safety and electromagnetic compatibility (EMC) of all electrical components of the device.
(6) Software verification, validation, and hazard analysis must be performed for all software components of the device.
(7) The patient-contacting components of the device must be demonstrated to be biocompatible.
(8) Performance data must validate the cleaning and disinfection instructions for reusable components of the device.
(9) Labeling must include the following:
(i) Information on how to operate the device and its components and the typical course of treatment;
(ii) A summary of the device technical parameters, including needle length, needle geometry, maximum penetration depth, and puncture rate;
(iii) Validated methods and instructions for reprocessing of any reusable components;
(iv) Disposal instructions; and
(v) A shelf life.
(10) Patient labeling must be provided and must include:
(i) Information on how the device operates and the typical course of treatment;
(ii) The probable risks and benefits associated with use of the device; and
(iii) Postoperative care instructions.