The ProM-300 is ProMedical Specialties top of the line TENS Unit. Its features include: Dual channel, 3 Modes: Standard, Modulate and Burst, Pulse Width Adjustable: 40-260, microseconds, Timer: 60 minutes, 30 minutes and continuous, Pulse Amplitude: Adjustable, 0-80mA each channel or – 20mA, peak maximum negative, Wave Form: Asymmetrical Bi-Phasic square.