The Wattstopper DT-355-U is a line-voltage ceiling-mount dual-technology occupancy sensor rated at 120/230/277/347 VAC, 50/60 Hz providing 360 coverage up to 1,000 sq ft at mounting heights of 812 ft for commercial ceiling applications. It combines PIR and 40 kHz ultrasonic detection with ultrasonic diffusers for comprehensive coverage, supports DIP-switch time delays (30 sec to 30 min), light level sensing (10300 fc), walk-through mode, test mode, and flying-lead termination compatible with BZ Power Packs and Wattstopper PLUS Sensor Interface Modules. Listed to UL, cUL; BAA/TAA compliant; USA manufactured; 5-year warranty.