• Electrochemical carbon monoxide sensor • Battery powered works during power outages • Front access battery door makes changing battery easier • 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 • 5 year limited warranty • Loud 85 decibel alarm • 10 inch x 6.63 inch x 2 inch • Manufacturer: First Alert • Model: CO400