EV-803(C) is a Digital SD TENS with 5 modes: B(Burst), N(Normal), M(Pulse Rate Modulation), S1(Pulse Width Modulation) and S2(Pulse Rate Modulation). Pulse rate, pulse duration and modes are selected by press buttons. A compliance meter allowing the physical therapist to check the accumulated treatment time. A timer of 15, 30 and 60 minutes and a protection cap on the top of unit is available by order. Cannel: Dual, isolated between channels Pulse Amplitude: 0-80mA peak to peak into 500 ohm load. Pulse Rate: Adjustable, from 1Hz ~ 150 Hz, 1 Hz/step Pulse Width: Adjustable, from 30 µs ~ 260 µs, 10 µs/step Mode: B, N, M, S1, S2 Wave Form: Asymmetrical Bi-Phasic Square Pulse Voltage: 0-40 V peak into 500 ohm load Size: 100(H)X 60(W) X 21(T) mm *A timer of 15, 30, 60 minutes is available by order.