First Alert Sealed Ionization 10 Year Smoke Alarm is powered by lithium battery for a full 10 years of protection without having to change the batteries. Tamper resistant design eliminates removal of batteries for other uses and ensures operation over the life of the alarm. Mute feature silences nuisance alarms from cooking smoke or shower steam. This smoke and fire alarm includes power LED and alarm indicator, end of life signal and single test/silence button so you can test your alarm regularly. For maximum protection and the ultimate in assurance, you can depend on First Alert to secure what matters most in life. Meets UL217 standards and includes a 10-year limited warranty.