The WattStopper PW-100 passive infrared (PIR) wall switch sensor turns lights ON and OFF based on occupancy. The PW-100 replaces existing wall switches and fits in a single gang junction box. It uses advanced PIR technology to detect occupancy and turn lighting ON. Once the space is vacated and the time delay elapses, lights automatically turn OFF. DIP switch settings allow for a variety of control options such as Auto-ON or Manual-ON operation, walk-through, and test modes.