510(k) · Cleared
ClearedGem-Twin Tens/ Models GM3XY/Z
Data to Oct 25, 2026 (FDA decisions) Oct 12, 2026 (recalls) Sep 30, 2026 (MAUDE) refreshed weekly
Gemore Technology Co, Ltd. · GZJ Stimulator, Nerve, Transcutaneous, For Pain Relief
Cleared on Nov 17, 2004 as substantially equivalent to K032720 (Gemore Technology Co, Ltd., 2003) and 2 other predicates after a 57-day review. Its family tree reaches back 3 generations to 1992. 2 later devices descend from it.
- Decided
- Nov 17, 2004
- Review
- 57 days
- Class
- Class II
- Product code
- GZJ
- Recalls
- None
- Predicates
- 3
Its longest line of descent runs back 3 generations to K921441 (1992). 9 ancestors in all. 2 later devices descend from it, 2 citing it directly.
- Root · 3 generations backK921441 Interferential Stimulator Model Inf 4150/aBiomedical Life Systems, Inc. · 1992
- 2 generations backK952683 Apex Medical Corp. Portable Interferential Stimulation DeviceWholesale Medical Imports, Inc. · 1997
- 1 generation backK032719 GM3 Series IF Tens, Model GM3X2IF (Where X IS a Parameter of…Gemore Technology Co, Ltd. · 2003
- This deviceK042559 Gem-Twin Tens/ Models GM3XY/ZGemore Technology Co, Ltd. · 2004
- Descendant · cites it directly · 0 of its ownK122948 Gem-Stim Combo StimulatorGemore Technology Co, Ltd. · 2012
- Descendant · cites it directly · 0 of its ownK082057 DX6605E-Tens, DX6605E-G, DX6609-GShenzhen Dongdixin Technology Co., Ltd. · 2009
Most influential descendants
Showing 2 of 2 · See allView FIG. 1 as a table
Line of descent and top descendants
| Generation | Number | Device | Applicant | Decided | Recalls |
|---|---|---|---|---|---|
| −3 | K921441 | Interferential Stimulator Model Inf 4150/a | Biomedical Life Systems, Inc. | 1992 | — |
| −2 | K952683 | Apex Medical Corp. Portable Interferential Stimulation Device | Wholesale Medical Imports, Inc. | 1997 | — |
| −1 | K032719 | GM3 Series IF Tens, Model GM3X2IF (Where X IS a Parameter of Different Housing) | Gemore Technology Co, Ltd. | 2003 | — |
| 0 (this device) | K042559 | Gem-Twin Tens/ Models GM3XY/Z | Gemore Technology Co, Ltd. | 2004 | — |
| +1 | K122948 | Gem-Stim Combo Stimulator | Gemore Technology Co, Ltd. | 2012 | — |
| +1 | K082057 | DX6605E-Tens, DX6605E-G, DX6609-G | Shenzhen Dongdixin Technology Co., Ltd. | 2009 | — |
Other ancestors by year cleared
| Year cleared | Devices | With a Class I recall |
|---|---|---|
| 1994 | 1 | 0 |
| 1995 | 1 | 0 |
| 2002 | 2 | 0 |
| 2003 | 2 | 0 |
Descendants by year cleared
| Year cleared | Devices | With a Class I recall |
|---|---|---|
| 2009 | 1 | 0 |
| 2012 | 1 | 0 |
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 GZJ? 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 GZJ device
- #1 K252767 actiTENS miniscore 13.1 · 9 generations · no Class I recall
- #2 Held for the reportin the report
- #3 Held for the reportin the report
What was it cleared against? (3)
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 |
|---|---|---|---|
| * | K032720 | Gem-Stim Tens, Models GM3XY and GM3AXYSummary page 1…preprogram TENS, "OPE" means preprogram EMS, "21F" means IF TENS, and "3HV" means high voltage TENS.. 3. Information of the 510(k) Cleared Device (Predicate Device): K032720, K032719 & K032994. 4. Device Description: The GEM-TWIN TENS series, including GM38Y/Z and GM39Y/Z(where Y and Z are any… | 2003 |
| * | K032719 | GM3 Series IF Tens, Model GM3X2IF (Where X IS a Parameter of Different Housing)Summary page 1…m TENS, "OPE" means preprogram EMS, "21F" means IF TENS, and "3HV" means high voltage TENS.. 3. Information of the 510(k) Cleared Device (Predicate Device): K032720, K032719 & K032994. 4. Device Description: The GEM-TWIN TENS series, including GM38Y/Z and GM39Y/Z(where Y and Z are any combina… | 2003 |
| * | K032994 | GM3 Series HV Tens, Model GM3X3HV (Where X IS Parameter of Different Housing)Summary page 1…PE" means preprogram EMS, "21F" means IF TENS, and "3HV" means high voltage TENS.. 3. Information of the 510(k) Cleared Device (Predicate Device): K032720, K032719 & K032994. 4. Device Description: The GEM-TWIN TENS series, including GM38Y/Z and GM39Y/Z(where Y and Z are any combination of OT… | 2003 |
What descends from it? (2)
2 later devices cite it directly; ranked here by how many devices descend from each in turn.
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?
- The line of descent spans 12 years and passes through 3 companies; a new generation was cleared every 4.9 years on median.
- None of the 9 ancestors has a recall.
- Of its descendants, K122948 (Gemore Technology Co, Ltd., 2012) has gone furthest, with 0 descendants of its own.
- 1 other device also cites its predicate K032720.
How does its category compare?
All GZJ devicesGZJ Stimulator, Nerve, Transcutaneous, For Pain Relief: FDA decisions, review times, recalls and adverse event reports over 20 years.
FDA decisions per year · GZJ
1in 2025
2026 to Oct 25, outlined.
Median 510(k) review, days · GZJ
207in 2024
Receipt to decision; years with fewer than 3 clearances left blank.
Recalls per year · GZJ
1in 2011
Class I (0 since 2007) Class II/III not classified
Adverse event reports per year · GZJ
13in 2025
MAUDE reports naming product code GZJ, 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 | 13 | 223 | 4 | 4 |
| 2008 | 11 | 136 | 1 | 45 |
| 2009 | 16 | 155 | 0 | 17 |
| 2010 | 5 | 232 | 0 | 22 |
| 2011 | 5 | 168 | 1 | 22 |
| 2012 | 12 | 154 | 0 | 20 |
| 2013 | 2 | — | 0 | 10 |
| 2014 | 4 | 344 | 0 | 23 |
| 2015 | 3 | 202 | 0 | 18 |
| 2016 | 3 | 163 | 0 | 32 |
| 2017 | 3 | 113 | 0 | 58 |
| 2018 | 2 | — | 0 | 21 |
| 2019 | 3 | 156 | 0 | 7 |
| 2020 | 4 | 183 | 0 | 10 |
| 2021 | 3 | 231 | 0 | 5 |
| 2022 | 4 | 175 | 0 | 4 |
| 2023 | 1 | — | 0 | 39 |
| 2024 | 3 | 207 | 0 | 12 |
| 2025 | 1 | — | 0 | 13 |
| 2026 | 2 | — | 0 | — |
What is it indicated for?
<1> If any one of "OT", "0PP", and/or "OTE" is mounted for Y or Z. This device is a prescription device and only for symptomatic relief of chronic intractable pain. <2> If any one of "0E", and/or "OTE" is mounted for Y or Z. * Relaxation of muscle spasms. * Prevention or retardation of disuse atrophy. * Increasing local blood circulation. * Muscle re-education. * Immediate post-surgical stimulation of calf muscles to prevent venous thrombosis. *…
Read the full statement (159 words)
<1> If any one of "OT", "0PP", and/or "OTE" is mounted for Y or Z.
This device is a prescription device and only for symptomatic relief of chronic intractable pain.
<2> If any one of "0E", and/or "OTE" is mounted for Y or Z.
* Relaxation of muscle spasms.
* Prevention or retardation of disuse atrophy.
* Increasing local blood circulation.
* Muscle re-education.
* Immediate post-surgical stimulation of calf muscles to prevent venous thrombosis.
* Maintaining or increasing range of motion.
<3> If any one of "OPE" is mounted for Y or Z.
* Relaxation of muscle spasms.
<4> If any "21F" is mounted for Y or Z
The device is an interferential stimulator with TENS indications used for symptomatic relief and management of chronic intractable pain.
<5> If any "3HV" is mounted for Y or Z
The device is an high voltage TENS device with TENS indications used for symptomatic relief and management of chronic intractable pain.
Indications for use as stated in the FDA summary.
https://510kreport.com/device/K042559 · printed Nov 6, 2026
Cite this page
510(k) Report. “K042559: Gem-Twin Tens/ Models GM3XY/Z.” Lineage record from FDA 510(k) data and the FDA summary. Updated Nov 3, 2026. Accessed Nov 6, 2026. https://510kreport.com/device/K042559
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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