Features: 1.Using microprocessor intelligent control, built-in voice chip, operation live voice prompts. 2.Backlight digital display alarm concentration, alarm work can be between AC90-240V. 3.With backup battery function, 9V Ni-MH rechargeable battery can be used. 4.High reliability dual sensor design, efficient and stable inductive transmission. 5.Sensor failure self-test function. Specification: Description:_x000D_ This product is a smart voice CO and flammable gas composite detector, using catalytic combustion sensors and advanced electrochemical CO sensors, with high stability and small sensitivity drift._x000D_ _x000D_ Features:_x000D_ _x000D_ Using microprocessor intelligent control, built-in voice chip, operation live voice prompts. _x000D_ Backlight digital display alarm concentration, alarm work can be between AC90-240V. _x000D_ With backup battery function, 9V Ni-MH rechargeable battery can be used. _x000D_ High reliability dual sensor design, efficient and stable inductive transmission. _x000D_ Sensor failure self-test function. _x000D_ Alarm memory function, you can view the alarm record at any time. _x000D_ The alarm sounds on the spot when the alarm is sounded. _x000D_ _x000D_ Specifications:_x000D_ _x000D_ Plug: US, EU, UK, AU.(Optional) _x000D_ External power supply: AC 90V-240V50-60Hz_x000D_ Built-in battery: 9V Ni-MH rechargeable battery_x000D_ Working temperature: 0-50C_x000D_ Operating Humidity: Relative humidity 10%-95%_x000D_ Display concentration:_x000D_ - Carbon monoxide: 100PPM999PPM (+50PPM)_x000D_ - Combustible gas: 0.25% 2% LEL (2500PPM-20000PPM1500ppm)_x000D_ Indicator information:_x000D_ - AC power: Green LED light_x000D_ - Alarm: Red LED flashes_x000D_ - Sensor failure: Yellow LED lights up_x000D_ Alarm sound: Live voice prompts and ringing siren_x000D_ _x000D_ Size: Approx. 11.3 * 7.5 * 4.5cm / 4.4 * 2.9 * 1.7in _x000D_ Weight: 60g_x000D_ _x000D_ Packing List:_x000D_ 1 * Alarm_x000D_ 1 * User Manual