Product Description: Easy to use: unique design, small, portable and easy wireless installation (screws included). Precise combined electro-optical sensor, high universal consistency and stability, movement or in the same place for this. Fast and loud danger alarm: alarm warning, when dangerous carbon monoxide gas concentration above 100ppm is detected, the red light flashes and a loud alarm pattern sounds, an alarm of 85 decibels. Clear LED display: protect the family from carbon monoxide, with optional 3-digit LED display "Err" on the LCD display to indicate the device is not working properly. First start condition: energy saving, powered by 3 x 1.5V AA batteries (included), the buzzer sounds "di", the detector starts preheating, it shows 2 minutes when the detector starts. Long Range Smoke Detector Protection Area: When the room height is 6-12m, the protection area of one detector is 80 square meters for general protection; the height of the room is 6m, the protection area is 60sqm