Digital timers simplify your life by automating repeating parts of your schedule, saving you time, energy and money. The EPC-A photosensor is an accessory sensor which detects ambient light level and uses that input to switch ON/OFF loads for your electrical automations. This sensor comes included with the DGLC-A series of digital time switches and may be ordered as an option for use with astro digital time switch models DGU100A and DGUM100A. The sensor is easy to install with a 1/2" threaded nipple and 180-degree swivel for even greater flexibility. When you need reliable photosensors for your digital time switches, trust in TORK, a pioneer in the electrical industry since 1922.