The AT-CT-1 Digital Cycle Timer can turn on/off electric appliances at precise intervals. A large backlit backlit digital display and buttons allow simple programming of the on and off duration from 1 second to 99 hours. The timer can be used in either manual or automatic modes. A photo sensor allows the timer to operate only at night, day or constantly. An internal battery stores programming in case of power failure. 120 Volts AC, 15 Amp On/Off time 1 second to 99 hours Manual or Automatic Modes Photo Sensor for Day / Night or Constant Operation Large backlit digital display