Check the listing for details. Testo 310 Combustion Analyzer Kit Measures O2 Flue Gas CO2 Manometer. Condition: For parts or not working. Listed at 275.00 USD. Comes with everything in pictures. Gives error message E04 and can not calibrate. EFFICIENT; The testo 310 co2 detector is ideal for more complex flue gas analyses, maintenance, safety checks, and furnace efficiency confirmations of residential heating systems VERSATILE; With its advanced sensor technology, the carbon monoxide meter offers accurate readings of O2, CO2, ambient CO, draft and pressure, temperature and combustion efficiency DURABLE; Thanks to its rugged housing with an integrated, kink-resistant hose, the gas leak detector is securely protected from impact and leaks EASY OPERATION; Equipped with a backlit display, quick-start and integrated condensation tap and magnet, the co2 monitor delivers a hands-free and easy application