Illuminate your path to safety with the First Alert SM210L Sealed 10-Year Battery Smoke Alarm with Safety Path Light. The SM210L smoke alarm also features First Alert's Precision Detection advanced sensing technology and meets new industry standards. The 10-year battery means no battery replacements for a decade. First Alert's Precision Detection advanced sensing technology complies with new industry standards to reduce cooking nuisance alarms and provides early warning in the event of a home fire emergency.