The Universal Security Instruments AMIC3511SB 3-in-1 Sensing Plus Smoke, Fire and Carbon Monoxide Alarm provides 10 years of continuous protection against deadly threats in the home. New Sensing Plus Multi-Criteria Detection provides the benefits of both photoelectric and ionization alarms in one device to protect against fast flaming and slow smoldering fires. This smart alarm also offers protection against the silent killer - carbon monoxide - making it a 3-in-1 detector. The ideal addition for new or replacement installations, this maintenance-free alarm is suitable for houses, apartments and mobile homes in every room.