Forget about turning your own lights off each morning to conserve energy. With the Woods 59405WD Photocell Light Sensor Socket Switch, that job is now automated. No special wiring or additional setup is required. Simply unscrew the bulb you currently have installed, replace it with the photocell and screw the bulb into the photocell socket. This smart device automatically detects outdoor light levels, meaning it will know when the sun goes down and comes up and turn your lights on and off accordingly. It?s also compatible with CFL, LED, mercury vapor, incandescent, and more types of bulbs. Maximum recommended usage is 100 Watts.