The Universal Security Instruments Hardwired MIC1509S 3-in-1 Smoke, Fire, and Carbon Monoxide Smart Alarm provides 10 years of continuous protection against three deadly threats within the home: smoke, fire, and carbon monoxide. New patented Universal Smoke Sensing Technology combines the advantages of both an ionization and photoelectric smoke detector in one device to protect against fast flaming and slow smoldering fires. This smoke detector carbon monoxide detector combo 10 year battery also features protection against the silent killer - carbon monoxide - making it an essential triple protection device. Perfect for both new installations and replacements, this hassle-maintenance-free alarm is an ideal choice for every room in homes, apartments, and mobile homes. The USI combination smoke alarm features an integrated backup battery that is sealed and never requires replacement for the entire lifespan of the alarm. This ensures a decade's worth of peace of mind even in the event of a power outage. The permanent power battery backup provides financial savings by eliminating the need to spend up to $38.00 on battery replacements over the alarm's 10-year lifespan and also cuts down on irritating low battery chirps. It also contributes to environmental conservation by reducing the waste generated from discarded batteries. This smoke and carbon monoxide detector is equipped with microprocessor intelligence that eliminates false alarms. It includes a silence/test button to quiet a non-hazardous alarm. Additionally, it features an end-of-service life warning, which activates approximately 10 years after the alarm is first activated, reminding you when it's time for a replacement. The Universal Security Instruments MIC1509S 3-in-1 Smoke, Fire, and Carbon Monoxide Smart Alarm comes with a 10-year limited warranty.