First Alert SC-9120B Hardwired Smoke & CO Alarm with Battery Backup - 2 Pack

Meet the First Alert SC-9120B Hardwired Smoke and Carbon Monoxide Alarm. This 2-pack delivers continuous protection with a built-in battery backup, so monitoring stays active even if the power dips or briefly fails.

Equipped with an electrochemical CO sensor and an ionization-based smoke sensor, it provides rapid detection in typical home environments. When linked with other BRK or First Alert hardwired detectors, you can create a coordinated safety net across your residence, helping you respond quickly to different risks.

Real-life benefits you may notice

In everyday scenarios, this system can help you notice smoke from cooking or a small fire and detect potentially dangerous CO buildup from heating systems. The two-pack design supports safety coverage on multiple floors or rooms where detectors are often needed most.

• Hardwired design with battery backup gives continuous monitoring during outages
• Interconnect capability allows alerts to ripple through compatible detectors for home-wide awareness
• Indicator lights clearly differentiate smoke from CO alarms at a glance
• Single test/silence button simplifies routine checks and temporary silences
• Side-load battery compartment enables quick maintenance without tools

Two units provide flexible placement for living rooms, hallways, bedrooms, and basements, supporting a practical safety setup for single-family homes. The SC-9120B emphasizes reliability, ease of use, and steady performance—without promising outcomes, but with clear potential for improved situational awareness.

Installation and ongoing care

Pair with compatible detectors to extend coverage across your home. Regularly test the alarms using the built-in button and replace batteries via the convenient side-load compartment as needed. Ensure the interconnects remain enabled so alerts can propagate when necessary.