The Wattstopper FS-L3W is a replacement polycarbonate lens for the FS-355 occupancy sensor, engineered for a 20 ft mounting height with 40 ft coverage in commercial fixture-mounted applications. One of four interchangeable FS-Lx lens options supporting mounting heights from 8 to 40 feet, it snaps onto the sensor from the fixture exterior for quick field installation. White finish; DLC qualified, RoHS compliant; compatible with FS-305 and FS-355 sensors; 5-year warranty.