# K042559: Gem-Twin Tens/ Models GM3XY/Z

- Pathway: 510(k) (Special)
- Applicant: Gemore Technology Co, Ltd.
- Decided: Nov 17, 2004 after 57 days
- Product code: GZJ (Stimulator, Nerve, Transcutaneous, For Pain Relief)
- Device class: 2
- Regulation: 21 CFR 882.5890
- Recalls of this device: none
- Data: FDA decisions to Oct 25, 2026; recalls to Oct 12, 2026

## Lineage
Longest line of descent: 3 generations back to K921441 (1992). 9 ancestors in all.
2 later devices descend from it; 2 cite it directly.
0 of 12 devices in its family (counting itself) have a Class I recall.

## Predicates on the family tree (from the FDA summary)
- K032720: Gem-Stim Tens, Models GM3XY and GM3AXY, Gemore Technology Co, Ltd. (2003) Summary page 1.
- K032719: GM3 Series IF Tens, Model GM3X2IF (Where X IS a Parameter of Different Housing), Gemore Technology Co, Ltd. (2003) Summary page 1.
- K032994: GM3 Series HV Tens, Model GM3X3HV (Where X IS Parameter of Different Housing), Gemore Technology Co, Ltd. (2003) Summary page 1.

## Most influential descendants
- K122948: Gem-Stim Combo Stimulator (2012), 0 descendants of its own
- K082057: DX6605E-Tens, DX6605E-G, DX6609-G (2009), 0 descendants of its own

## Indications for use
<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.

Source page: https://510kreport.com/device/K042559
Methodology: https://510kreport.com/methodology