The Pain Remedy Plus Wireless TENS/EMS System is a battery operated wireless pulse generator that sends electrical impulses from a REMOTE control to a RECEIVER (round) with ELECTRODES attached to it. The Wireless REMOTE controls the INTENSITY and MODE functions of the RECEIVER. The LCD display shows the mode value, channel number, battery life, and intensity level. Because the Pain Remedy Plus System is wireless - needing no lead wires - you must use only Pain Remedy SNAP Electrodes. Lead wire type electrodes will not work with this wireless system.