The Quad-Stim is a combination Transcutaneous Electrical Nerve Stimulation (TENS) and Electrical Muscle Stimulation (EMS) digital device used for pain relief, relaxation, and stimulating muscles. The device has four controllable and independent output channels, each of which can be connected to an electrode pair. The battery operated device has a swing-door panel of individually controlled pulse amplitude intensity levels, ranging from 1 to 100. The device has adjustable pulse rate and width, 5 TENS modes, 3 EMS modes, 2 adjustable timers, 24 preset programs, and can store up to 60 sets of operation records. Now available as an Over-The-Counter device!