The First Alert CO710A is a battery powered carbon monoxide alarm with a 10-year sealed lithium battery. The alarm can be installed without any need to replace batteries annually. It features a built-in LCD screen to display status when a button is pressed or carbon monoxide is detected. Since it is battery powered, the alarm can be placed wherever it's needed, with no need for a wall outlet. The peak level feature lets you see not just the current levels of carbon monoxide (if any), but the peak level reached. The loud built-in 85dB siren sounds when the CO is detected to alert family members. The CO710A is for use indoors and is appropriate for homes, cottages, R's, or motor homes in bedrooms, basements, living rooms, or near fireplaces or appliances that may potentially emit carbon monoxide. The CO710A uses an electrochemical sensor for increased accuracy and features an easy access battery door, mute/silence button, and end of life timer to alert when replacement is needed.