The SONOSTAT 133 is an ergonomically designed unit that works at 1 and 3 MHz frequencies, and is the ideal system for those wanting an easy handling unit as a starter unit for ultrasonic therapy procedures. The SONOSTAT 133 uses two treatment heads, one measuring 2.5 square centimeters and the other measuring 5 square centimeters. Both treatment heads are watertight, of robust construction, and friendly to the skin. Either treatment head can be used at either of the two frequencies, with the frequency being selected on the unit's front control panel.