The USI AMI3051SB 2-in-1 Sensing Plus® Smoke & Fire Alarm provides 10 years of continuous protection against fast-flaming and slow-smoldering fires. Sensing Plus® Multi-Criteria Detection combines the benefits of both photoelectric and ionization technology in one device. Perfect for houses, apartments, and mobile homes, it features a sealed 10-year battery that never needs replacing, offering uninterrupted protection during power outages while saving money, eliminating low battery chirps, and reducing waste. Microprocessor intelligence helps prevent nuisance alarms, while the silence/test button provides quick operation. An end-of-life warning signals when it’s time for replacement. Designed for new installations or easy replacement of existing USI alarms, it includes a large mounting base to cover drywall imperfections. Installation is simple with a quick-activation pull tab, and the deactivation key powers off the alarm for safe disposal. UL 217 (8th edition) compliant and California State Fire Marshal and FHA approved, this alarm exceeds industry standards.