Dual frequency four-channel can be used independently or in combination with Pre-modulated, Interferential, Russian and High Volt waveforms. Features: 1 and 3.3 MHz frequencies, 10%, 20%, 50% and continuous duty cycle selections with head warming. Bright-lit back LCD display. Includes 5 cm soundhead and a 9 oz. bottle of Conductor Gel. 2 year warranty.