Has 10 intensity options and 6working mode options. Four LED display Will close automatically after 12 minutes normal staring. It will return to "open" status without touching the skin during 3 seconds of normal starting; also it will close automatically during 20 seconds of "open" status without pressing any button. Generates electronic impulses when the muscle exercise unit is working. Press the ON/INC button again when power is on, the muscle training units start working, the intensity is level one, the mode is mode A. It powered by 2pcs Li-ion button batteries, which can last for a long time. Color: silver.