Portable Stim Therapy The Metron Pro TENS Unit with Timer and Carry Case is a regular TENS with adjustable pulse width, pulse rate, intensity, modes and an accurate timer of 15, 30 and 60 minutes, which will stop output at preset time. Specifications: Channel: dual, isolated between channels; modes of operations: continuous, burst, modulation; pulse intensity: adjustable 0-80mA peak into 500 ohm load each channel, constant current; pulse rate: 2Hz-150Hz (adjustable); pulse width: 30?s - 260?s (adjustable); time: continuous, 30 min, 60 min; burst mode: burst consists 2 bursts per sec at 100 Hz; wave form: asymmetrical bi-phasic square pulse; voltage: 0-100 volt (open current); power source: 9 volt battery; dimensions: 95(H) x 60(W) x 23(D) mm; weight: 115 grams (battery included); warranty: 1 Year.