First Alert CO400 Battery Operated Carbon Monoxide Alarm

First Alert CO400 Battery Operated Carbon Monoxide Alarm: Features an electrochemical carbon monoxide sensor Battery powered so it works during power outages Front access battery door makes changing the battery easier Has a silence and test button No installation required, just place or mount almost anywhere Alarm action chart instructs on what to do if an alarm sounds UL listed 7-year limited warranty on theFirst Alert carbon monoxide alarm Alerts with a loud 85-decibel alarm 10" x 6.63" x 2" 0.65 lbs