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%.Accuracy: O2: &plun;0.2%, CO: &plun;10 PPM < 100 PPM else &plun;5% of reading, CO2: &plun;0.3% reading, Temp. (Flue and net): &plun;2°C &plun;0.3% reading, Efficiency: &plun;1% reading, Excess Air: &plun;0.2%.Resolution: O2: 0.1%, CO: 1 PPM, CO2: 0.1%, Temp. (Flue and net): 0.1°F/C, Efficiency: 0.1%, Excess Air: 0.1%.Ambient Operating Temperature: 32 to 104°F (0 to 40°C).Power Requirements: 4 AA batteries or optional AC adapter.Pre-Programmed Fuels: Natural Gas, Light Oil, Propane, Butane, LPG, and Wood Pellets.Probe: 11.8" (300 mm) length x 0.25" (6 mm) diameter with 7.8" (200 mm) stainless steel shaft.Hose: 10 ft (3 m).Weight: 1.7 lb (0.77 kg).Agency Approvals: CE.