CoolTone

K251378 · Zimmer Medizinsysteme GmbH · NGX · Jul 14, 2025 · Physical Medicine

Device Facts

• Record ID: K251378
• Device Name: CoolTone
• Applicant: Zimmer Medizinsysteme GmbH
• Product Code: NGX · Physical Medicine
• Decision Date: Jul 14, 2025
• Decision: SESE
• Submission Type: Special
• Regulation: 21 CFR 890.5850
• Device Class: Class 2
• Attributes: Therapeutic

Intended Use

Improvement of abdominal tone, strengthening of the abdominal muscles, development for firmer abdomen. Strengthening, toning and firming of buttocks and thighs.

Device Story

CoolTone is a non-invasive, mobile powered muscle stimulator used in clinical settings by healthcare providers. It generates a magnetic field via two large applicators applied to the patient's abdomen, buttocks, or thighs. The device uses a securement system to maintain applicator position. Operation is controlled via a 12-inch color touch screen, where the user selects pre-set treatment options (abdomen, buttocks, thighs) and adjusts parameters including frequency, time, and intensity. The device induces muscle contraction by initiating action potentials in nerves. Treatment is continuous, up to 30 minutes per session. The output helps strengthen, tone, and firm the targeted muscle groups, providing a non-surgical aesthetic benefit to the patient.

Clinical Evidence

No clinical testing was required for this submission.

Technological Characteristics

Powered muscle stimulator; Class I, BF electrical protection. Energy source: 100-240 VAC, 50-60 Hz. Magnetic field intensity: 0.5–1.35T. Waveform: Symmetrical Biphasic Sine Wave. Pulse duration: 370 μs +/- 20%. Frequency: 1-150 Hz. Materials: Steel and injection-molded plastics. User interface: 12-inch touch screen. Connectivity: Standalone mobile unit. Software-controlled.

Indications for Use

Indicated for improvement of abdominal tone, strengthening of abdominal muscles, development of firmer abdomen, and strengthening, toning, and firming of buttocks and thighs in adult patients.

Regulatory Classification

Identification

A powered muscle stimulator is an electrically powered device intended for medical purposes that repeatedly contracts muscles by passing electrical currents through electrodes contacting the affected body area.

Predicate Devices

• CoolTone (K220601)

Submission Summary (Full Text)

{0}

FDA U.S. FOOD & DRUG ADMINISTRATION

July 14, 2025

Zimmer MedizinSysteme GmbH
% Scott Blood
Principal Consultant
QARA Consulting
151 Gleasondale Road
Stow, Massachusetts 01775

Re: K251378
Trade/Device Name: CoolTone
Regulation Number: 21 CFR 890.5850
Regulation Name: Powered Muscle Stimulator
Regulatory Class: Class II
Product Code: NGX
Dated: June 16, 2025
Received: June 16, 2025

Dear Scott Blood:

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 (the 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 available 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.

Additional information about changes that may require a new premarket notification are provided in the FDA guidance documents entitled "Deciding When to Submit a 510(k) for a Change to an Existing Device"

U.S. Food & Drug Administration
10903 New Hampshire Avenue
Silver Spring, MD 20993
www.fda.gov

{1}

K251378 - Scott Blood

(https://www.fda.gov/media/99812/download) and "Deciding When to Submit a 510(k) for a Software Change to an Existing Device" (https://www.fda.gov/media/99785/download).

Your device is also subject to, among other requirements, the Quality System (QS) regulation (21 CFR Part 820), which includes, but is not limited to, 21 CFR 820.30, Design controls; 21 CFR 820.90, Nonconforming product; and 21 CFR 820.100, Corrective and preventive action. Please note that regardless of whether a change requires premarket review, the QS regulation requires device manufacturers to review and approve changes to device design and production (21 CFR 820.30 and 21 CFR 820.70) and document changes and approvals in the device master record (21 CFR 820.181).

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 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 (reporting of medical device-related adverse events) (21 CFR Part 803) for devices or postmarketing safety reporting (21 CFR Part 4, Subpart B) for combination products (see https://www.fda.gov/combination-products/guidance-regulatory-information/postmarketing-safety-reporting-combination-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 Part 4, Subpart A) for combination products; and, if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR Parts 1000-1050.

All medical devices, including Class I and unclassified devices and combination product device constituent parts are required to be in compliance with the final Unique Device Identification System rule ("UDI Rule"). The UDI Rule requires, among other things, that a device bear a unique device identifier (UDI) on its label and package (21 CFR 801.20(a)) unless an exception or alternative applies (21 CFR 801.20(b)) and that the dates on the device label be formatted in accordance with 21 CFR 801.18. The UDI Rule (21 CFR 830.300(a) and 830.320(b)) also requires that certain information be submitted to the Global Unique Device Identification Database (GUDID) (21 CFR Part 830 Subpart E). For additional information on these requirements, please see the UDI System webpage at https://www.fda.gov/medical-devices/device-advice-comprehensive-regulatory-assistance/unique-device-identification-system-udi-system.

Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR 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-devices/medical-device-safety/medical-device-reporting-mdr-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/medical-devices/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-devices/device-advice-comprehensive-regulatory-assistance/contact-us-division-industry-and-consumer-education-dice) for more information or contact DICE by email ([e-mail]) or phone [phone] or 301-796-7100).

{2}

K251378 - Scott Blood

Sincerely,

Tushar Bansal -S

Tushar Bansal, PhD
Assistant Director, Acute Injury Devices Team
DHT5B: Division of Neuromodulation and
Physical Medicine Devices
OHT5: Office of Neurological and
Physical Medicine Devices
Office of Product Evaluation and Quality
Center for Devices and Radiological Health

Enclosure

{3}

DEPARTMENT OF HEALTH AND HUMAN SERVICES
Food and Drug Administration
Indications for Use
Form Approved: OMB No. 0910-0120
Expiration Date: 07/31/2026
See PRA Statement below.

Submission Number (if known)
K251378

Device Name
CoolTone

Indications for Use (Describe)
- Improvement of abdominal tone, strengthening of the abdominal muscles, development for firmer abdomen.
- Strengthening, toning and firming of buttocks and thighs.

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
[e-mail]

"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."

{4}

K251378
510(K) SUMMARY

SUBMITTER:
Zimmer MedizinSysteme GmbH
Junkersstrasse 9
89231 Neu-Ulm, Germany
Establishment Registration: 8010720

CONTACT:
Mrs. Ute Killet
Manager, Regulatory Affairs
Phone: [phone]
Fax: [phone]
E-mail: [e-mail]

DATE PREPARED:
May 30, 2025

TRADE NAME:
CoolTone

COMMON NAME:
Powered Muscle Stimulator

CLASSIFICATION NAME:
Stimulator, Muscle, Powered, For Muscle Conditioning

DEVICE CLASSIFICATION:
Class II, 21 CFR §890.5850

PRODUCT CODE:
NGX

PREDICATE DEVICE:
CoolTone (K220601)

DEVICE DESCRIPTION:
The CoolTone is a non-invasive therapeutic device. The device produces an electromagnetic field that interacts with the tissues of the human body. By muscle stimulation, the CoolTone helps to strengthen, tone and firm abdomen, buttocks and thighs.

The device housing protects the patient from electrical shock and mechanical injuries. The device is a mobile standalone equipment with four wheels.

Two large applicators are connected to the control unit and can be used simultaneously depending on the treatment. The device is a medical equipment that generates a magnetic field by applying a strong current to an applicator. The CoolTone is equipped with the

{5}

securement system which is designed to maintain applicator position throughout treatment.

A large color touch screen facilitates the use of the device. The on-screen information guides the user step-by-step through the entire treatment process. The treatment is operated through parameters such as frequency, time and intensity. Three pre-set treatment options are available for users to choose from: Abdomen, buttocks and thighs.

# INDICATIONS FOR USE:

CoolTone is indicated to be used for:

- Improvement of abdominal tone, strengthening of the abdominal muscles, development for firmer abdomen.
- Strengthening, Toning and Firming of buttocks and thighs.

# COMPARISON OF TECHNOLOGICAL CHARACTERISTICS WITH THE PREDICATE DEVICE:

The technological characteristics of the subject device and the predicate device are identical.

Table 1: Technological Similarities between Proposed and Predicate Device

| Technological Characteristics | SUBJECT DEVICE Zimmer MedizinSyteme GmbH CoolTone (K251378) | PREDICATE DEVICE Zimmer MedizinSyteme GmbH CoolTone (K220601) |
| --- | --- | --- |
| Product Code and Regulation | Physical Medicine 21 CFR 890.5850 NGX – Stimulator Muscle, Powered, Muscle Conditioning | Physical Medicine 21 CFR 890.5850 NGX – Stimulator Muscle, Powered, Muscle Conditioning |
| Indications for Use | The CoolTone is indicated to be used for: • Improvement of abdominal tone, strengthening of the abdominal muscles, development of firmer abdomen. • Strengthening, Toning and Firming of buttocks and thighs. | The CoolTone is indicated to be used for: • Improvement of abdominal tone, strengthening of the abdominal muscles, development of firmer abdomen. • Strengthening, Toning and Firming of buttocks and thighs. |
| Primary Function | Muscle stimulation | Muscle stimulation |

{6}

| Technological Characteristics | SUBJECT DEVICE Zimmer MedizinSyteme GmbH CoolTone (K251378) | PREDICATE DEVICE Zimmer MedizinSyteme GmbH CoolTone (K220601) |
| --- | --- | --- |
| Principle of Action | Initiating action potential of nerves results in muscle contraction | Initiating action potential of nerves results in muscle contraction |
| Electrical Protection | Class I, BF | Class I, BF |
| User Interface | Touch screen | Touch screen |
| Touch screen size | 12" | 12" |
| Positioning of Applicator | Securement system | Securement system |
| Firmware Controlled | Yes | Yes |
| Type of Energy | Magnetic field | Magnetic field |
| Magnetic Field Intensity | Large applicator 0.5 – 1.35T +/- 20% | Large applicator 0.5 – 1.35T +/- 20% |
| Number of outputs | 2 | 2 |
| Number of Magnetic Coils in the Applicator | 1 | 1 |
| Number of applicators | Up to two large applicators can be operational at same time | Up to two large applicators can be operational at same time |
| Applicator connection | Detachable from the control unit | Detachable from the control unit |
| Total Induced Current in Tissue (mA) | 327 | 327 |
| Type of Operation | Continuous | Continuous |
| Pulse Repetition Rate | 1 – 150 Hz | 1 – 150 Hz |
| Pulse Duration | Large applicator 370 μs +/- 20% | Large applicator 370 μs +/- 20% |
| Pulse Amplitude | 0 – 100 % | 0 – 100 % |
| Selection of parameters (Intensity, Time) | Yes | Yes |
| Treatment Time | Up to 30 min | Up to 30 min |
| Shape of Stimulation Pulse | Symmetrical Biphasic Sine Wave | Symmetrical Biphasic Sine Wave |
| Energy Source | 100 - 240 VAC, 50-60 Hz | 100 – 240 VAC, 50–60 Hz |
| System Dimensions (WxHxD) | 600 x 1100x 600 mm | 600 x 1100x 600 mm |
| Operating Ambient Temperature | 10°C to 28 °C | 10°C to 28 °C |
| Environmental Specifications | For indoor use only | For indoor use only |

{7}

Table 2: Technological Similarities between Proposed and Predicate Device per FDA Guidance for Industry for Powered Muscle Stimulators for 510(k)s (June 9, 1999)

| Sections 2,3 Technological Characteristics | SUBJECT DEVICE Zimmer MedizinSyteme GmbH CoolTone (K251378) | PREDICATE DEVICE Zimmer MedizinSyteme GmbH CoolTone (K220601) | Comments |
| --- | --- | --- | --- |
| 4. Power Source(s) - Method of Line Current Isolation - Patient Leakage Current Normal condition Single fault condition | 60601 compliant < 100 μA 3.9 μA | 60601 compliant < 100 μA 3.9 μA | 60601 Compliant |
| 5. Number of Output Modes | 1 | 1 | |
| 6. Number of Output Channels - Synchronous or Alternating? - Method of Channel Isolation | 2 Synchronous N/A | 2 Synchronous N/A | No electrodes - applicators are not connected to patient |
| 7. Regulated Current or Regulated Voltage? | Voltage | Voltage | Controlled voltage to the coil |
| 8. Software/Firmware/Microprocessor Control? | Yes | Yes | |
| 9. Automatic Overload Trip? | N/A | N/A | No electrodes - applicators are not connected to patient |
| 10. Automatic No-Load Trip? | N/A | N/A | No electrodes - applicators are not connected to patient |
| 11. Automatic Shut Off? | Yes | Yes | Unit shuts off with specified timer |

{8}

| Sections 2,3
Technological
Characteristics | SUBJECT DEVICE
Zimmer MedizinSyteme
GmbH
CoolTone (K251378) | PREDICATE DEVICE
Zimmer MedizinSyteme
GmbH
CoolTone (K220601) | Comments |
| --- | --- | --- | --- |
| 12. Patient Override
Control? | No | No | Treatment is
delivered by
health care
provider |
| 13. Indicator Display:
- On/Off Status?
- Low Battery?
- Voltage/Current
Level? | Yes
N/A
No | Yes
N/A
No | |
| 14. Timer Range
(minutes) | Up to 30 Min | Up to 30 Min | |
| 15. Compliance with
Voluntary Standards? | Yes | Yes | |
| 16. Compliance* with
21 CFR 898? (*Becomes
mandatory beginning
May 9, 2000) | Yes | Yes | |
| 17. Weight | 80 Kg | 80 Kg | |
| 19. Housing Materials
and Construction | Steel and Injection Molded
Plastics | Steel and Injection
Molded Plastics | |
| Waveform (e.g., pulsed
monophasic, biphasic) | Symmetrical Biphasic Sine
Wave | Symmetrical Biphasic Sine
Wave | |
| Shape (e.g., rectangular,
spike, rectified
sinusoidal) | Sinusoidal | Sinusoidal | |
| Maximum Output
Voltage (specify units) | N/A | N/A | No electrodes
- applicators
are not
connected to
patient |
| Maximum Output
Current (specify units) | N/A | N/A | No electrodes
- applicators
are not
connected to
patient |
| Pulse Width (specify
units) | 370 μs +/- 20% | 250-400 μs +/- 20% | |
| Frequency (Hz) | 1-150 Hz | 1-150 Hz | |

{9}

| Sections 2,3 Technological Characteristics | SUBJECT DEVICE Zimmer MedizinSyteme GmbH CoolTone (K251378) | PREDICATE DEVICE Zimmer MedizinSyteme GmbH CoolTone (K220601) | Comments |
| --- | --- | --- | --- |
| For interferential modes only: - Beat Frequency (Hz) | N/A | N/A | |
| For multiphasic waveforms only: - Symmetrical phases? | Yes | Yes | Biphasic |
| Phase Duration (include units) (state range, if applicable) (both phases, if asymmetrical) | 370 μs +/- 20% | 370 μs +/- 20% | |
| Net Charge (mC per pulse) (If zero, state method of achieving zero net charge.) | N/A | N/A | No electrodes - applicators not connected to the patient |
| Maximum Phase Charge, (mC) | N/A | N/A | No electrodes - applicators not connected to the patient |
| Maximum Current Density, (mA/cm2) | N/A | N/A | No electrodes - applicators not connected to the patient - see SAR report |
| Maximum Power Density, (W/cm2)(using smallest electrode conductive surface area) | N/A | N/A | No electrodes - applicators not connected to the patient |
| Burst Mode7 (i.e., pulse trains) a. Pulses per burst b. Bursts per second c. Burst duration (seconds) d. Duty Cycle [Line (b) x Line (c)] | N/A | N/A | |
| ON Time (seconds) | N/A | N/A | |

{10}

| Sections 2,3 Technological Characteristics | SUBJECT DEVICE Zimmer MedizinSyteme GmbH CoolTone (K251378) | PREDICATE DEVICE Zimmer MedizinSyteme GmbH CoolTone (K220601) | Comments |
| --- | --- | --- | --- |
| OFF Time (seconds) | N/A | N/A | |
| Additional Features (if applicable) | N/A | N/A | |

## Product Labeling

This premarket submission included changes in product labeling. The user's manual was updated to capture information obtained in post-market surveillance activity. The labeling changes described in the submission do not affect the intended use, performance or risk profile of the device.

## Clinical Study

No clinical testing was required for this change.

## Substantial Equivalence Determination

a. Intended Use: There is no change to the indications for use for this submission between the subject and predicate device (K220601).
b. Technological Characteristics: The CoolTone has the same technological characteristics as the predicate device (K220601).
c. Labeling: The changes in labeling described in this submission does not create any new questions of safety and performance as compared to the predicate device.

The CoolTone is substantially equivalent to the predicate K220601.