" 2-IN-1 DETECTION: Alerts you to both smoke and carbon monoxide (CO) using a single detector. NEVER-CHANGE 10-YEAR BATTERY: No low battery chirps or battery changes for 10 years and saves up to 40 Dollar over the life of the detector. (10-yr limited warranty on alarm, not a battery performance claim.) ENHANCED SENSING TECHNOLOGY: Reduces false smoke alarms often caused by cooking. Comprehensively tested to meet the latest UL standards, meets UL 217 9th Edition, UL 2034 4th Edition, and FCC standards. SELF-TESTING ALARM: Internal components ensure alarm is always operating as expected. Not a substitute for a manual push test, perform a button test once per week to verify alarm operation. 3 LED NOTIFICATIONS: LED lights indicate alarm status, green - normal operation, amber - operating error, red - smoke or carbon monoxide detected and a loud 85-decibel alarm will sound. › See more product details"