Outdoor Twist-To-Lock Photocell Sensor, Can Be Used On Sports Fields, Parking Lots, Commercial Buildings, Street Lights Or Other NEMA Locking Plug Type Connections, Turns Light On At Dusk & Off At Dawn, Locking Type Plug Configuration, Works With Incandescent, Fluorescent, LED, Halogen, Mercury Vapor Or High Pressure Sodium Bulbs, CFL Compatible, Time Delay Eliminates False On/Off Triggers, CUL Listed.