Prowave 400sx160 ultrasonic transducers open type aluminium housing prowave 400sr160 this ultrasonic ceramic transducer is an open type transmitter that come in a robust aluminium housing applications include remote control data transmission doppler motion detectors robotics intruder alarms energy saving devices etc a matched transmitter is also available see 35 0175 prowave 400st160 40khz aluminium ultrasonic transmitter open type