The CO100 is a desktop indoor air quality CO₂ monitor that measures carbon dioxide concentrations (CO₂) from 0 to 9,999ppm, air temperature and humidity. With user programmable visible and audible CO₂ warning alarm. Meter has a maximum/minimum CO₂ value recall function. Maintenance free NDIR (non-dispersive infrared) CO₂ sensor. Complete with Universal AC adaptor.