Universal Security Instruments Hardwired 10 Year Tamper Proof Permanent Power Sealed Battery 3-in-1 Universal Smoke Sensing & Carbon Monoxide Combination Alarm, Model MIC1509S 3-in-1 Smart Alarm provides continuous, reliable protection. Provides temperature and humidity compensation Smart Alarm Technology provides peace of mind with this alarm  Fast-and-easy installation suitable for houses, apartments, dormitories and more Features microprocessor intelligence to virtually eliminate nuisance alarms Features quick activation battery pull tab that makes the alarm easy to install while the deactivation key makes it the batteries safe for disposal Comes with a ten-year limited warranty