510(k) · Cleared
ClearedLi-Battery Powered OTC TENS/EMS Combination Stimulator, Model Z4
Data to Oct 25, 2026 (FDA decisions) Oct 12, 2026 (recalls) Sep 30, 2026 (MAUDE) refreshed weekly
Everyway Medical Instruments Co.,Ltd · NUH Stimulator, Nerve, Transcutaneous, Over-The-Counter
Cleared on Nov 21, 2025 as substantially equivalent to K201335 (Everyway Medical Instruments Co.,Ltd, 2020) after a 157-day review. Its family tree reaches back 1 generation to 2020.
- Decided
- Nov 21, 2025
- Review
- 157 days
- Class
- Class II
- Product code
- NUH
- Recalls
- None
- Predicates
- 1
Its longest line of descent runs back 1 generation to K201335 (2020). No later device cites it as a predicate yet.
- Root · 1 generation backK201335 Li-Battery powered OTC TENS/EMS Combination StimulatorEveryway Medical Instruments Co.,Ltd · 2020
- This deviceK251856 Li-Battery Powered OTC TENS/EMS Combination Stimulator, Model Z4Everyway Medical Instruments Co.,Ltd · 2025
View FIG. 1 as a table
Line of descent and top descendants
| Generation | Number | Device | Applicant | Decided | Recalls |
|---|---|---|---|---|---|
| −1 | K201335 | Li-Battery powered OTC TENS/EMS Combination Stimulator | Everyway Medical Instruments Co.,Ltd | 2020 | — |
| 0 (this device) | K251856 | Li-Battery Powered OTC TENS/EMS Combination Stimulator, Model Z4 | Everyway Medical Instruments Co.,Ltd | 2025 | — |
Sources: FDA 510(k) database (decision fields), the FDA summary (predicates and indications), FDA recall and enforcement reports, and MAUDE; processed by 510(k) Report. Verify on FDA.gov · Methodology and accuracy.
Planning a device in NUH? A 510(k) Report weighs predicate choices, recall history and review times for a new device like this one.
Top candidate predicates for a new NUH device
- #1 K190783 Health Expert Electronic Stimulator (model…score 15.8 · 7 generations · no Class I recall
- #2 Held for the reportin the report
- #3 Held for the reportin the report
What was it cleared against? (1)
Devices the submitter claimed this one is substantially equivalent to (*), and reference devices cited for a specific test or feature (†), as written in the FDA summary.
| Type | Number | Device | Decided |
|---|---|---|---|
| * | K201335 | Li-Battery powered OTC TENS/EMS Combination StimulatorSummary page 5…red muscle stimulator Regulation Numbers: 21 CFR 882.5890 and 21 CFR 890.5850 Product Codes: NUH and NGX Regulatory Class: II III. PREDICATE DEVICE 510(k) Number: K201335 Name of Device: Li-Battery powered OTC TENS/EMS Combination Stimulator, Models EV- 906/EV-906A Regulation Names: Transcutaneou… | 2020 |
What descends from it?
No later submission names this one as a predicate yet.
Has anything in its family been recalled? (0 Class I)
No FDA recall names this device.
No ancestor or descendant has a Class I recall.
What does this lineage say?
- Its one ancestor has no recall.
How does its category compare?
All NUH devicesNUH Stimulator, Nerve, Transcutaneous, Over-The-Counter: FDA decisions, review times, recalls and adverse event reports over 20 years. 2025, this device’s year, is highlighted.
FDA decisions per year · NUH
15in 2025
2026 to Oct 25, outlined.
Median 510(k) review, days · NUH
119in 2025
Receipt to decision; years with fewer than 3 clearances left blank.
Recalls per year · NUH
No recall names NUH since 2007.
Adverse event reports per year · NUH
7in 2025
MAUDE reports naming product code NUH, not matched to any one device; reports are not rates.
View these four charts as a table
| Year | Decisions | Median 510(k) review, days | Recalls (Class I) | MAUDE reports |
|---|---|---|---|---|
| 2007 | 4 | 161 | 0 | 0 |
| 2008 | 0 | — | 0 | 0 |
| 2009 | 1 | — | 0 | 0 |
| 2010 | 3 | 148 | 0 | 0 |
| 2011 | 6 | 231 | 0 | 0 |
| 2012 | 6 | 170 | 0 | 0 |
| 2013 | 10 | 189 | 0 | 1 |
| 2014 | 16 | 212 | 0 | 9 |
| 2015 | 14 | 198 | 0 | 11 |
| 2016 | 13 | 145 | 0 | 13 |
| 2017 | 17 | 155 | 0 | 21 |
| 2018 | 16 | 121 | 0 | 18 |
| 2019 | 19 | 213 | 0 | 5 |
| 2020 | 14 | 147 | 0 | 8 |
| 2021 | 14 | 198 | 0 | 7 |
| 2022 | 20 | 103 | 0 | 2 |
| 2023 | 15 | 127 | 0 | 4 |
| 2024 | 20 | 90 | 0 | 7 |
| 2025 | 15 | 119 | 0 | 7 |
| 2026 | 5 | 137 | 0 | — |
What is it indicated for?
1. The Z4 Li-Battery Powered OTC TENS/EMS Combination Stimulator is intended for over-the- counter (OTC) use. It integrates both TENS and EMS functions in a single unit. However, the device can only operate in one mode (either TENS or EMS) at a time; simultaneous operation of both modes is not possible. 2. TENS is intended for temporary relief of pain associated with sore and aching muscles in the low back as well as upper and lower extremities (arm…
Read the full statement (121 words)
1. The Z4 Li-Battery Powered OTC TENS/EMS Combination Stimulator is intended for over-the- counter (OTC) use. It integrates both TENS and EMS functions in a single unit. However, the device can only operate in one mode (either TENS or EMS) at a time; simultaneous operation of both modes is not possible.
2. TENS is intended for temporary relief of pain associated with sore and aching muscles in the low back as well as upper and lower extremities (arm and/or leg) due to strain from exercise or normal household and work activities. (Choose TENS Modes P1 to P19 programs)
3. EMS is intended to stimulate healthy muscles in order to improve or facilitate muscle performance. (Choose EMS Modes P20 to P30 programs)
Indications for use as stated in the FDA summary.
https://510kreport.com/device/K251856 · printed Nov 5, 2026
Cite this page
510(k) Report. “K251856: Li-Battery Powered OTC TENS/EMS Combination Stimulator, Model Z4.” Lineage record from FDA 510(k) data and the FDA summary. Updated Nov 3, 2026. Accessed Nov 5, 2026. https://510kreport.com/device/K251856
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Record history
- FDA decision record loaded May 2, 2026
- Summary read Oct 13, 2026 (extraction version 9eaa42aa01ed)
- Lineage and recalls computed Nov 3, 2026
- Page last updated Nov 3, 2026