Cleared Special

K251856 - Li-Battery Powered OTC TENS/EMS Combination Stimulator, Model Z4 (FDA 510(k) Clearance)

Class II Neurology device cleared through the Special 510(k) pathway - typically does not require clinical trials.

K251856 · Everyway Medical Instruments Co.,Ltd · Neurology device
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Optimized for regulatory review, auditing and printing
Nov 2025
Decision
157d
Days
Class 2
Risk

K251856 is an FDA 510(k) clearance for the Li-Battery Powered OTC TENS/EMS Combination Stimulator, Model Z4. Classified as Stimulator, Nerve, Transcutaneous, Over-the-counter (product code NUH), Class II - Special Controls.

Submitted by Everyway Medical Instruments Co.,Ltd (New Taipei City, TW). The FDA issued a Cleared decision on November 21, 2025 after a review of 157 days - an extended review cycle.

This device falls under the Neurology FDA review panel, regulated under 21 CFR 882.5890 - the FDA neurology device framework. As a Special 510(k), this submission covers a manufacturer modification to an existing cleared device rather than a new device introduction.

Device pattern: Iterative device modification. Standard predicate reliance. This Special 510(k) clearance confirms that the manufacturer's modifications remained within the established regulatory envelope of the original cleared device.

View all Everyway Medical Instruments Co.,Ltd devices

Submission Details

510(k) Number K251856 FDA.gov
FDA Decision Cleared Substantially Equivalent - Traditional 510(k) (SESE)
Date Received June 17, 2025
Decision Date November 21, 2025
Days to Decision 157 days
Submission Type Special
Review Panel Neurology (NE)
Summary Summary PDF
Third-party Review No - reviewed directly by FDA
Combination Product No
PCCP Authorized No
Regulatory Context
Review time vs. panel average
9d slower than avg
Panel avg: 148d · This submission: 157d
Pathway characteristics
Modification to existing cleared device.

Device Classification

Product Code NUH Stimulator, Nerve, Transcutaneous, Over-the-counter
Device Class Class 2 - Special Controls
CFR Regulation 21 CFR 882.5890
Definition Temporary Relief Of Pain Due To Sore/aching Muscles
What this classification means

Class II devices require demonstration of substantial equivalence to a legally marketed predicate device. This pathway does not require clinical trials - it relies on engineering equivalence and performance data. Most Neurology devices follow this clearance model.

Regulatory Peers - NUH Stimulator, Nerve, Transcutaneous, Over-the-counter

All 226
Devices cleared under the same product code (NUH) and FDA review panel - the closest regulatory comparables to K251856.
TENS/EMS device (GUSE01)
K253896 · Globalcare Medical Technology Co., Ltd. · Mar 2026
TENS AND EMS (TENS and Muscle Stimulator) (JT1065, JT1080, JT2080, JT9034)
K253305 · Shenzhen Jiantuo Electronics Co., Ltd. · Dec 2025
VEINOPLUS Back
K251958 · Dynapulse Medical · Dec 2025
TENS&EMS (HZ9151B, HZ9151C, HZ9151D)
K253740 · Hong Qiangxing (Shenzhen) Electronics Limited · Dec 2025
Transcutaneous Electrical Nerve Stimulator (RJTENS-2)
K252688 · Bozhou Rongjian Medical Appliance Co., Ltd. · Nov 2025
Triathlon Pro
K243131 · Sigma Biomedical · Nov 2025