The WVR Series sensors are a cost effective answer to retrofitting classrooms with inaccessible ceilings. Additionally, these self contained line voltage sensors do not require neutral, meaning the sensor can wire directly off local switches! Typical retrofits utilize wiremold coming out of a local switch up to the sensor's mounting location. In new construction, an electrical junction box can be located in the wall with the sensor wired to interrupt the feeds to the switches. The WVR Series sensors use Passive Infrared (PIR) detection technology. For rooms with obstructions the WVR PDT 16 Series is recommended. For two pole applications, the see the WVR 16 2P and WVR PDT 16 2P Series.