Electronic nerve stimulation provides temporary pain relief to shoulders, waist, back, neck, arms or legs.. Small pad is 3 x 2 inches and large pad is 6-1/2 x 3-1/2 inches: Both are activated wirelessly.. There are four pulse modes and 20 intensity levels.. Gel-style electrode pads. Reusable electrodes can be used up to 50 times.. 30-minute fixed timer so device will shut off automatically. Single-channel output. 1-year limited warranty.