First Alert BRK SC9120B 85-Decibel Ionization Hardwired Smoke and Electrochemical Carbon Monoxide Detector with Battery Backup

This First Alert SC9120B Hardwired Smoke and Carbon Monoxide Detector includes a 9-volt battery backup that continues to protect you in the event of a power failure. One button silences any nuisance alarms， and also tests detector functions， while lights indicate if the alarm detects smoke or carbon monoxide. The latching alarm indicator automatically identifies which unit initiated the alarm， even after the conditions that set off the alarm have subsided. And an end-of-life signal enhances your safety by letting you know when it’s time to replace the unit.

• Features an electrochemical Carbon Monoxide sensing technology as well as an ionization sensor that detects the fine particles of a fast-burning fire
• Indicator lights on the face of the unit display the presence of smoke or carbon monoxide， while an 85-decibel siren provides a clear， loud warning upon detection
• Simple to use， with a single test/silence button， and side-load battery compartment; tamper-resistant locking brackets and universal mounting brackets make installation easy
• Rigorously tested to meet UL standards