Optional High Volt / DC Probe * The microprocessor-controlled Sonicator Plus 940 is a four channel combination unit * It combines 1 and 3 MHz ultrasound with eight treatment waveforms: Interferential Premodulated Medium Frequency (Russian) EMS High Volt TENS Microcurrent and Direct Current (DC). All waveforms are available on all four channels * A dual-frequency 5.5 cm