The WS-250 Passive infrared (PIR) Wall Switch Sensor turns lighting on and off based on occupancy and ambient light level. It replaces existing wall switches and fits behind a standard decorator wall plate. The WS-250 improves on the WS-200, featuring a shallower housing, flying leads and new control button.FEATURES AND BENEFITS:- 180° coverage, maximum of 900 ft2- Shallow (1”) back housing and flying leads for easy installation- Built-in light level sensor- Button provides positive tactile feedback- Dual voltage model, 120/277VAC- Compatible with all electronic ballasts