Range:O2: 0 to 21%, CO: 0 to 2000 PPM (4000 PPM Max for 15 minutes), CO2: 0 to 30%, Temp. (Flue and net): 32 to 1112°F (0 to 600°C), Efficiency: 0 to 99.9%, Excess Air: 0 to 250%.
Ambient Operating Temperature:32 to 104°F (0 to 40°C).
Power Requirements:(8) AA alkaline batteries, installed functional, user replaceable, (4) AA NiMH batteries, included, user replaceable (charger included) or optional power adapter.