Quell Q1400 Photoelectric Smoke Alarm Lithium Sealed Battery each

Photoelectric sensor Advanced sensor that detects visible particles associated with smouldering fires. Central Hush/Test button Easy to operate. Tests the alarm circuitry and horn and silences nuisance alarms. Sealed-in lithium battery Maintenance and hassle free with prevention from tampering and removal. The alarm is always on, with no battery replacement required for the 10-year life span of the alarm.