OSFOA is a two piece plastic offset that installs into the fixture 1/2-inch knockout using the provided lock-nut For deep body fixtures, the OSFOA gives the sensor full field-of-view Helps improve the field-of-view for deep body fixtures For use with Leviton occupancy sensors (OSFHU) Leviton offers a wide selection of motion sensors that use passive infrared, ultrasonic or a combined multi-sensing technology case of 10 offset adapter accessories