First Alert 10 Year Smoke & Carbon Monoxide Alarm

Photoelectric smoke sensor reduces nuisance alarms. Electrochemical carbon monoxide sensor monitors carbon monoxide levels. Features 10-year alarm life with sealed 3 volt lithium battery which eliminates replacing batteries. Low profile design is half the thickness of standard alarms. Power led (light emitting diode) and alarm indicator. Dimensions: 5.67″ x 1″ x 5.67″.