The Adjustable Recycle Timer by Custom Automated Products controls any application requiring a device to be turned on and off at precise intervals. TheAdjustable Recycle Timer has a user adjustable on time of 1 second to 40 minutes and an off time of 1 minute to 8 hours. A day/night/both switch allows you to select the time period that the Adjustable Recycle Timer will operate. The Adjustable Recycle Timer timers have a wide range of uses including controlling hydroponic pumps, simple CO2 controller, turning on and off ozone generators, running exhaust fans, etc. Adjustable Recycle Timers are rated for 15 amps @ 120 volts. Three year warranty.