First Alert Hardwired Smoke Alarm Hardwired smoke alarm featuring 10-year battery backup. Equipped with an ionization sensor, reliably detects smoke from fast flaming fires and alerts you with an 85-decibel alarm. Includes adapter plugs that eliminate the need for re-wiring during installation. Designed for easy accessibility with single button for testing and silencing, universal mounting bracket included for easy installation. Type Hardwired, Voltage 120V, Sensor Type Ionization, Dimensions 5.6 In. W. x 2 In.H. x 5.6 In. L., Battery Back-up Yes, Alarm Type Smoke, Decibel Level 85dB, Battery Type 9V Battery, Batteries Included Yes, Color White, UL Listed Yes, Warranty 10-Year Limited, Pkg Qty 1, Package Type Card