Drive Electrical Muscle Stimulation (EMS) helps in the treatment of muscle injury by delivering mild, electronic pulses into the muscle replicating passive exercises. The EMS relaxes and loosens tense muscle tissue, encouraging blood flow to the area and building up the muscle. Drive's Digital Electronic Muscle Stimulator will help you rehab from injury. EMS unit comes with it's own carrying case, 2 lead wires, a 9-volt battery, a pack of 4 electrodes and an instruction manual.