JM 1ST APPROACH

Three Mode with Timer TENS - is a dual Channel device with three modes of operation (B, N, and M). Its pulse width and pulse frequency are adjustable. It is also equipped with a 30, 60, 90 minute timer, and has a protective cover over the controls
Technical Specifications:
Channels: Dual Channels, Isolated between channel.Modes: Normal. Modulation Mode: Pulse width is automatically varied in a cyclic pattern over an interval of nominally 4.0 Seconds.
Burst Mode: 7 pulses per burst / 2 bursts per second / 100 Hz internal frequency of burst.
Timer: 30,60,constant
Power Source: 9V DC square shape battery