FIRST ALERT CO400-3 Carbon Monoxide Detector, Battery Operated, White, 3-Pack

Reliable CO Monitoring, Ready When You Are

Meet the FIRST ALERT CO400-3 Carbon Monoxide Alarm set — a trio of battery-powered detectors designed for flexible placement without wiring. Each unit relies on an electrochemical carbon monoxide sensor, a trusted standard for detecting CO quietly and accurately across living spaces. The included 9-volt batteries power the alarms, ensuring coverage even during power outages. With a simple one-button interface, these detectors are easy to test, silence, and manage as part of your home safety routine.

Why this 3-pack matters

• Three detectors provide coverage on every level and in sleeping areas, helping to create balanced CO awareness throughout the home.
• Electrochemical CO sensors deliver dependable readings and respond to suspected leaks from appliances, chimneys, or generators.
• An audible 85-decibel alarm sounds to alert you when CO levels rise, giving you time to respond calmly and effectively.

The CO400-3 units are designed for straightforward placement—no wiring required. They can be positioned on shelves, desks, or walls with the optional wall mount. A visible and audible low-battery signal helps you know when to replace the battery so coverage stays uninterrupted.

Easy to use, practical features

• One-button test/silence operation makes checks quick and simple.
• End-of-life timer guides replacement to maintain reliable protection; the permanent sensor lasts up to five years.
• UL-listed construction and compliance with CO requirements in several states provide additional assurance.

What’s in the box? A 3-pack of FIRST ALERT CO400-3 carbon monoxide detectors, with included replaceable 9-volt batteries for immediate setup. This kit is designed for all 50 states and aligns with current safety guidelines in California, Wisconsin, and Oregon. While alarms can significantly improve situational awareness, they are not a substitute for safe home practices. Use this kit as part of a broader safety plan to reduce risk and respond promptly if an alarm sounds.

Practical setup tips

• Place one detector on each level and in each sleeping area for broad coverage.
• Test the units regularly and replace batteries as needed to maintain readiness.
• Use the optional wall mounting to keep detectors out of reach of children while staying visible.

UL listed and designed for reliability, the FIRST ALERT CO400-3 3-pack offers a practical, non-wiring solution for informed, proactive CO monitoring across your home.