TENS kit provides temporary pain relief to shoulders, waist, back, neck, arms or legs.. Electrode pads adhere to skin with an effective but gentle, gel-style adhesive.. Apply two or four pads at a time: Wires carry low voltage electrical current from TENS unit to pads.. Eight pulse frequency modes and 18 intensity levels. Electrodes can be used up to 50 times.. Programmable timer of 10 – 60 minute therapy sessions. Dual-channel output. Internal battery is rechargeable..