Medzer Peripheral Nerve Stimulator relieves chronic pain by modulating nerve signals with 36 massage modes ranging from 0 to 104 Hz. It features an adjustable timer from 10 to 60 minutes with a default of 20 minutes, a 200mAh battery, and a dual-channel output for simultaneous use. https://www.medzer.com/peripheral-nerve-stimulator/pns-1000a