First Alert 10-Year Battery Slim Round Carbon Monoxide/Smoke Alarm Slim photoelectric smoke and carbon monoxide alarm with 10-year battery helps protect homes from two potentially deadly threats by providing up to a decade of uninterrupted monitoring. Equipped with dual sensors, detects smoke from slow-burning, smoldering fires. Half as thick as a standard alarm, features a slim, contemporary design that mounts unobtrusively on a wall or ceiling. Includes a built-in 10-year lithium-ion battery provides continuous power, with no need to ever worry about changing the battery during the lifetime of the alarm. Type Battery Operated, Voltage 3V, Battery Life 10 Yr. Battery, Sensor Type Photoelectric/Electrochemical, Dimensions 5.67 In. W. x 1 In. H. x 5.67 In. L., Battery Back-Up Battery Only, Alarm Type Smoke Carbon Monoxide, Decibel Level 85dB, Battery Type 3V Lithium Battery, Batteries Included Yes, Color White, UL Listed No, Warranty 10-Year Limited, Pkg Qty 1, Package Type Clamshell