Twin Stim TENS and EMS combo. Our most popular digital electrotherapy unit. The Twin Stim gives the user the choice of 5 modes of TENS and 2 Modes of EMS. Twin Stim's features include Dual Channel 7 modes, Timer, Patient Compliance Meter, 100mA output, safety amplitude cover, sturdy metal belt clip, rubber side railings for maximum handling. Channels: Dual Channel, isolated between channels. Pulse Amplitude: Adjustable 0-100 mA peak into 500 ohm load each channel. Voltage: 0 - 50V (Load: 500 ohm). Pulse Rate: Adjustable from 2 to 150 Hz 1 Hz/step. Pulse Width: Adjustable from 50 to 300 microseconds 10uS/step. Wave Form: Asymmetrical Bi-Phasic Square Pulse. On Time: Adjustable 2~90 seconds 1 Sec./ step. Off Time: Adjustable 2~90 seconds 1 Sec./ step. Ramp Time: Adjustable 1~8 seconds 1 Sec./ step The On time will increase and decrease in the setting value. 3 EMS Modes: Constant Synchronous Alteate. Constant stimulation based on setting value. Only pulse width ,pulse rate and timer are adjustable in this mode. Constant is equal to the Normal mode of a TENS unit. Synchronous: Stimulation of both channels occurs synchronously. 5 Modes: B(Burst) N(Normal) M(Modulation) SD1(Strength Duration) SD2. System Includes: Stimulator, Lead Wires, 1 package of high quality Self-Adhesive Electrodes, 9V Battery, Hard Plastic Carrying Case & Instruction Booklet.