BRK Smoke Alarm with 10 Year Battery. 10-Year Sealed 3V Lithium Battery, for continuous protection. Includes Ionization smoke sensing technology.No battery replacements required for the life of the alarm.Eliminates low battery chirps. No low battery chirps for a decade. 10-year smoke sensor and end of life signal. Provides audible notice when the alarm needs to be replaced. Test/Silence Button, temporarily silence or test the alarm with one-touch, easy access button. Cannot be Hardwired. 10 Year Limited Warranty. Model SMI110.