Tens Unit Dual Channel 3 Mode w/Timer

System includes device lead wires four self-adhesive reusable electrodes 9v battery hard plastic carrying case and instruction manual. 3 modes: standard modulate and burst. Dual channel. 30 and 60 minutes or continuous timer. Adjustable pulse width: 50-250 microseconds. Pulse rate: 2-150 hz. Pulse amplitude: 0-80 ma each channel. Waveform: asymmetrical biphasic square pulse. One year warranty. Fda approved. Prescription required.