Watt Stopper  

WS-250 Passive Infrared Wall Switch Sensor
Price $66.52
Ideal for home or office, this wall switch sensor detects motion in areas up to 900 square feet, and saves power by automatically turning lights out when a room is empty.

PW-100 Passive Infrared Wall Switch Sensor
Price $78.39
This attractively designed energy-saving sensor uses Passive Infrared (PIR) technology to detect motion, and automatically turns lights off when you leave the room.

UW-100 Ultrasonic Wall Switch Sensor
Price $103.76
Able to sense both ambient light and room occupants, this sensor saves you money by turning the lights on only when there are people in the room, and only if additional light is needed.

DW-100 Dual Technology Wall Switch Sensor
Price $131.33
Combining the best features of ultrasonic and passive infrared technologies, these sensors are able identify and adjust to usage patterns, maximizing your energy savings.