First Alert Slim Round Photoelectric Carbon Monoxide/Smoke Alarm Battery-operated combination photoelectric smoke and carbon monoxide alarm packs premium detection capabilities into a sleek, compact design. Comes equipped with dual sensors for reliable detection of two potentially deadly threats. Battery life varies according to use and application. Type Battery Operated, Voltage 3V, Battery Life Varies According To Application, Sensor Type Photoelectric, 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 AA Battery, Batteries Included Yes, Color White, UL Listed No, Warranty 7-Year Limited, Pkg Qty 1, Package Type Clamshell