Engineered with class and simplicity, the operations of this unit are straightforward and easy to implement, without any issues. We love this smoke detecting alarm system because it is one with a lot of positive reviews from users all over the world. These users attest to the high durability of this unit and recommend it strongly for all households and offices. The First Alert Smoke Detector Alarm features a 6 pack hardwired alarm system with a backup battery that kicks in anytime there’s a power failure. One major feature of this smoke detector is its ionization sensor, a feature that enables your alarm system detects smoke being emitted from fast flaming fires. The alarm produced to keep users alert is generated at 85 decibels, a sound level that is adequate during emergencies, no matter where you are, you’re assured of safety.