First Alert Slim Photoelectric Smoke Alarm with 10-Year Sealed Battery, PR710, White

Complies with all current 10-year legislation in U.S. states/cities where required
Slim shape is half as thick as a standard smoke alarm; easy twist-lock mounting system and tamper-resistant design
Equipped with photoelectric smoke sensor optimized to detect larger smoke particles produced by smoldering fires; helps minimize the number of false alarms