2 in 1 detector: It can be served as both Smoke detector and carbon monoxide detector alarm to detect the threat from these two harmful chemicals,Very suitable for carbon monoxide gas leakage and fire place, Once the smoke and carbon monoxide detector detects these two gases, they will beep..LCD Display: smoke detector carbon monoxide detector combo LCD digit indicates real-time carbon monoxide (CO) concentration in the surrounding air, as well as the battery levels. A low battery warning （“LB”）lets you know it is time to change the battery; a smoke warning (“HHH”) lets you know that a smoke fire is happening..Three Alarm Mode: 85dB Buzzer & LED & Human Voice Warning. The 85dB loud buzzer with rapid flashing red indicator light will warn you when dangerous smoke or CO concentration is detected. The smoke alarm carbon monoxide alarm will emit clearly human voice warning to warn the kids and the oldster to escape the dangerous..Accurate & All-Around Protection: It will ensure that smoke triggers the alarm instead of interference by taking 3 separate smoke samples from the surrounding air .360° air inlet ring ensures complete accurate inspection without blind spots. Ensure whole family protection with 24hours monitoring by placing 1 carbon monoxide detector on each level of your home, in your bedroom, habitable portions of basements and attics, and more..Simple to Use & Easy Installation: The test/silence button operation of this smoke carbon monoxide alarm enables you to test the alarm weekly, easily silence when false alarms. Battery powered 2-in-1 carbon monoxide fire alarm with the included screws, anchor plugs ,requires no rewiring, easy to mount on any wall or ceiling.