The Telaire 7001 hand held Carbon Dioxide sensor features patented Absorption Infrared technology. Each sensor measures CO2 and Temperature and will calculate and display real-time ventilation rates. When combined with the HOBO U12 or ZW Series it can record CO2 and when connected to the H22 or U30 Series it can record Temperature & CO2. The Telaire comes with an adapter but also operates up to 70 hours on 4 AA batteries (not included).