Isolated channels. Protective caps over amplitude adjustment knobs. Symmetrical balanced sine wave output. Two or four pad. 4,000 Hz fixed carrier frequency (CH 1). Pulse intensity is adjustable 0 – 60 mA peak each channel, constant current. Adjustable 4004 – 4160 Hz modulating frequency (CH 2). 4 – 160 bps, adjustable 4 bps/step interference pulse frequency. Timer can be set for 15- or 30-minute treatment. Patient compliance feature allows prescribing doctor to monitor patient’s usage of the device. Patient lock system prevents user from changing any fixed parameters set by physician. Utilizes standard lead wires and pigtail-style electrodes. Includes two lead wires, four electrodes (one pack), hard plastic carrying case, instructions and AC adapter. One year warranty.