The First Alert Combination Smoke and Carbon Monoxide Alarm detects two threats, smoke and carbon monoxide, in a single device. This 2-in-1 hardwired alarm has lights on the face of the …

The First Alert SC9120B Hardwired Combination Smoke and Carbon Monoxide Alarm is a hardwire alarm with battery backup. The hardwired detector includes a 9-volt battery backup …

On a peaked, gabled, or cathedral ceiling, install the first Smoke/CO Alarm within 3 feet (0.9 meters) of the peak of the ceiling, measured horizontally. Additional Smoke/CO Alarms may …

Feb 7, 2025 · Using a 9-volt backup battery, the smoke and carbon monoxide detector can function even in the event of a power outage. Additionally, the Co smoke alarm features a …

Jan 1, 2008 · Quick plug-in power connector for easy installation. 120-volt AC inter-connectable with BRK and First Alert hardwired smoke and carbon monoxide alarms. This 2-in-1 …

Manual First Alert SC9120B. View the First Alert SC9120B manual for free or ask your question to other First Alert SC9120B owners.

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. The alarm features …

The SC9120B hardwire alarm comes with 2-in-1 protection to detect CO you can"t see, smell or taste in the air, as well as first signs of a potential fire. This alarm works exceptionally well by …

Nov 10, 2025 · Find the exact First Alert replacement model that connects directly to your existing SC9120B wiring harness.

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