The Watt Stopper UT-355 360 degrees ultrasonic occupancy sensors operate on 120VAC, 230VAC, 277VAC or 347VAC. The UT-355 turns lighting systems on and off based on occupancy. SmartSet technology allows the sensor to be installed with minimal adjustments. SmartSet automatically adjusts the time delay to usage patterns in the controlled space. The sensors can be con?gured to turn lighting on, and hold it on as long as it detects occupancy. After no movement is detected for the user specifed time or the SmartSet time (5 to 30 minutes) the lights are switched off. A walk-through mode can turn lights off after only 3 minutes, if no activity is detected after 30 seconds of an occupancy detection.