# K212989: Low-frequency Stimulator (Model: AST-645, AST-646)

- Pathway: 510(k) (Traditional)
- Applicant: Shenzhen Osto Technology Co., Ltd.
- Decided: Nov 22, 2021 after 63 days
- Product code: NUH (Stimulator, Nerve, Transcutaneous, Over-The-Counter)
- 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: 9 generations back to K881114 (1988). 62 ancestors in all.
No later device cites it as a predicate yet.
0 of 63 devices in its family (counting itself) have a Class I recall.

## Predicates on the family tree (from the FDA summary)
- K191151: JKH Stimulator Plus, Jkh USA, LLC (2019) Summary page 4.
- K190783: Health Expert Electronic Stimulator (model: AST-300L), Shenzhen Osto Technology Company Limited (2020) Summary page 5.

## Indications for use
TENS: To be used for temporary relief of pain associated with sore and aching muscles in the shoulder, waist, back, back of the neck, arm, leg, and foot due to strain from exercise or normal household work activities by applying current to stimulate nerve. It is also intended for symptomatic relief and management of chronic, intractable pain and relief of pain associated with arthritis. PMS: It is intended to stimulate healthy muscles in order to improve and facilitate muscle performance. Heating: It is intended for temporary relief of minor aches and pains.

Source page: https://510kreport.com/device/K212989
Methodology: https://510kreport.com/methodology