The model WB-800 Operates on 12 or 24 Volt AC/DC and has a form C relay output that can be connected to alarm panels, bells, AutoDialers, etc. Unit also includes internal alarm buzzer with silence switch and eight LEDs on console to identify the sensor in alarm. As many as eight supervised sensor probes can be run up to 500 feet away (or 16 non-supervised sensors). Each sensor probe has two contacts. When a film of water forms a bridge between these contacts, the unit senses this and triggers the alarm output. The sensor will not alarm due to condensation or high humidity. Four supervised surface sensors are included with the unit. The use of supervised sensors allows the WB800 to monitor the condition of the wire and sensor.