The AIR-4 has all the features of the AIR-3 with the addition of independent temperature and humidity controls. It also has an increased power capacity to control up to 15 amps of equipment. An additional outlet is provided which will power equipment only during the 'day' cycle. Features include independent temperature and humidity control, coordinated CO2 sequencing and an additional outlet that is powered only while the lights are on. The AIR-4 is rated for 15 amps @ 120 volts.