This controller makes it easy to coordinate your exhaust and CO2 production. The CO2-2e Controller has 2 timers that allow for efficient control of CO2 levels, one controls how often CO2 is released and the other controls how long it is released. It also features temperature and humidity controls that will stop CO2 production and activate the exhaust outlet if the levels that you set are exceeded. A photosensor disables CO2 production while the lights are off. May be upgraded to PPM level control with the addition of the PPM-1c. Rated for 15 amps @ 120 volts. 3 year no hassle warranty.