We offer a great selection of Photocell Switches from Danlers are great cost-effective switches ideal for applications in schools, factories and hospitals and the like. For the Ceiling Switches, these switches turn lights off when there is sufficient ambient light but require the wall switch to be operated in order to switch on. In this way the lights only switch on when they are demanded. And when the isnt sufficient light the switches turn on the lights. A great cost effective and time saving method to save energy!