The Wattstopper UT-355-1 is a low-profile ultrasonic line-voltage ceiling occupancy sensor that automatically controls lighting based on occupancy in private offices, restrooms, and small commercial spaces. Rated for 100347VAC operation, it provides 500 sq ft of ultrasonic detection coverage without requiring a separate low-voltage power supply or control panel. Its line-voltage design simplifies installation in standard commercial applications where direct switching is required.