The EMS 5.0 unit uses electrical impulses to contract and relax muscles helping those who experience muscle tension in the upper back and neck areas. Can be used to regain muscle strength after surgery or after being in a cast. The EMS unit is portable and may be clipped to a belt, shirt, pocket or other clothing. System includes device, lead wires, four self-adhesive reusable electrodes, 9-volt battery, hard plastic carrying case and instruction manual. 105 mA strong. Power Source: 9-volt battery. Channel: Dual, isolated between channels. Pulse Width: 250 microseconds. Pulse Rate: 5, 30, 100 Hz. Pulse Ramp: 1, 3, 5 seconds. Pulse Amplitude: Adjustable, 0-80 mA. Contraction Control: 1-30 seconds. Relaxation Control: 1-45 seconds. Wave Form: Asymmetrical Bi-Phase Square Pulse.