Environment controllers control any application requiring a device to be turned on and off at precise intervals. This timer has a wide range of uses including controlling hydroponic pumps, CO2 injection, turning on and off exhaust fans, misters and more. Autopilot Analog Recycling Timer cycle timer with day/night detection. There is no programming required it is easy to set and operate. Cycle timing is adjustable for operation during the day, night, or 24 hours.