The RPS-409A analog ultrasonic sensor is a self contained sensor in a 30mm PVC barrel housing. It is powered by 20-30VDC with reverse polarity protection. It also has a narrow beam angle which enables it to get into tight places. A flat target can tilt up to 10 degrees and still be detected. The RPS-409A has a short circuit protected analog 0-10 VDC output. The output is a linear .125 volts per inch. Example: a target placed 10 inches from the sensor will result in an output signal of 10 volts.