The Autopilot REVOLVE F20 Repeat Cycle and Light Combo Timer controls lighting schedules and timed cycling functions in your grow area with perfect digital accuracy. It has simultaneous dual timer functions, a 24-hour time clock for lighting, and a precision cycle timer for pumps, CO2 injection, exhaust fans, intake fans, etc. that allow you to dial in programming down to the second. REVOLVE F20 has four outlets. Two outlets control light(s)/light mover(s); one cycle timed outlet controls a pump, exhaust fan or other recycling device; and one outlet controls a nighttime device such as a heater, dehumidifier, or exhaust fan. All four outlets feature heavy duty protective covers that prevent atmospheric moisture from entering the device through any unused outlets.