A user programmable time delay ensures that once the room is vacated the sensor will time out and turn off the lights. WSD Series sensors have operating modes such as Reduced Turn On Sensitivity and Switch Disable that are all fully programmable using the front push-button. Features auto sensitivity adjustment, small detection up to 20 ft., intrinsically grounded, adjustable time delay and green LED indicator. UL and CUL Listed. PDT Series Switches feature Dual Technology with PIR / Microphonics detection. Sensors with Passive Dual Technology (PDT) first see motion using Passive Infrared (PIR) and then engage Microphonics to hear sounds that indicate continued occupancy. Uses Automatic Gain Control (AGC) to dynamically self adapt a sensor to its environment by filtering out constant background noise and detecting only noises typical of human activity.