APEX Lighting Store stocks a variety of different photo sensor, shortening caps and photocells. Photocells are the light-sensitive components within photosensors. All the components of a photosensor are referred to as a photosensor, including the housing, the optics, the electronics, and the photocell. Also referred to as dusk-to-dawn photocontrols which turn lights on and off according to the time of day. Parking lots and street lights are examples of applications for these lights, which save energy both indoors and outdoors. These are Rain-tight for outdoor use. Preset time delay prevents unintended switching from flashes due to headlights, lightning and other transitory lighting sources.