"AV voltage: AC 90V-240V 50-60Hz Battery voltage: 9V rechargeable battery (optional) Working temperature: 0°C-50°C Warm-up time: about 180S Ambient humidity: 10%-95% Sound level: 85dB / m Alarm concentration display Carbon monoxide gas: 100PPM~999MM (±50PPM) Combustible gas: 0.25%~2% LEL (2,5500PPM~20,000PPM±1,500PPM) Alarm: vocal alert and siren alarm"