We have two in MINT condition. Control your Humidity/CO2 Levels/ Temperature/Night Device Plug. The “AIR4” Atmospheric Controller is used in conjuction with the “C.A.P.” BRAND “PPM-4” CO2 Controller UNIT and are sold as separate units. The “C.A.P.” BRAND “PPM4” is sold separately and is needed to measure the CO2 levels in the grow room. We have two of these as well and they are listed on the menu.