10 Year Smoke Alarm, Utilizes Both Ionization & Photoelectric Smoke Sensors For Optimal Performance, Intelligent Sensing Technology Reduces Non-Emergency Or Nuisance Alarms, Powered By Sealed, 10 Year Lithium Batteries To Provide Continuous Protection For 10 Years Without Battery Replacement, Emits A Loud 85 Decibel Alarm For Ample Warning, Meets UL217 Standards & Complies With Legislative Requirements For 10 Year Battery Operated Smoke Alarms.