The First Alert SMI100 Battery-Operated Smoke Alarm is easy to install and features First Alert's Precision Detection advance sensing technology. The front access battery compartment makes for quick battery replacements and a low battery warning will advise when it's time to replace. Discourage unwanted removal of the battery or smoke alarm using the optional locking features. Use the convenient test/silence button on the front of the smoke alarm to check that it is operating properly and silence false alarms. An end-of-life warning will advise you when it’s time to replace because alarms don't last forever. Effortlessly install the CO400 Battery-Operated Carbon Monoxide Alarm throughout your home for reliable CO protection in minutes. Operation is simple. Test the CO alarm using the single test/silence button. The low battery warning will notify you when it's time to replace the alarm's battery, which is quick process due to the front access battery door, and an end-of-life warning will alert you when it's time to replace the alarm all together.

working good no problems easy installl. Jack. Prescott, MI. Sat Jul 25 2026

Reliable Carbon Dioxide Monitor for Indoor and Outdoor Environments: Monitor CO₂ levels effortlessly with our carbon dioxide monitor. High-accuracy infrared sensing ensures stable readings across different concentrations. With long-lasting battery power of 72-120 hours on standby and intuitive operation, it is ideal for outdoor spaces, offices, classrooms, and labs.

Good. Ginger Mamma . Sun Jun 28 2026

This plug-in electrochemical explosive gas and carbon monoxide alarm features a backlit digital display, this explosive gas, and CO detector plugs into any AC outlet with no additional mounting hardware needed.

It's an alarm -it seems to work -haven't had a chance to truly try it out -which is good -so that is all I have to say about that lol. Kimberly. Boston, MA. Tue Mar 10 2026

This First Alert carbon monoxide alarm features a 10-year built-in lithium battery for continuous monitoring during the life of the alarm, and uses an electrochemical carbon monoxide sensor and an 85-decibel alarm to alert you to CO threats. The advanced electrochemical CO sensor detects carbon monoxide leaks from multiple sources, such as faulty fuel-burning appliances, blocked chimneys, and generators running inside or too close to homes. Because CO evenly distributes itself, it's important to have a CO detector on every level and in every bedroom of your home. This easy-to-use alarm features a digital display that shows ambient temperature as well as peak CO levels. The detector's stylish design looks great on top of a dresser or table.

Love the product… Easy to setup…Test Alarm feature is also very helpful.. Vamsi. US. Sun May 14 2023

The First Alert SMI100-AC Interconnect Hardwire Smoke Alarm with Battery Backup meets new industry standards utilizing First Alert's Precision Detection advanced sensing technology. This hardwire smoke alarm is easy to install and replace existing detectors with no need to rewire. Plus interconnect compatible alarms to create a whole home alarm system to help provide an early warning. First Alert's Precision Detection advanced sensing technology complies with new industry standards to reduce cooking nuisance alarms and provides early warning in the event of a home fire emergency.

Easily install the First Alert SMCO200 Battery-Operated Combination Smoke & Carbon Monoxide Alarm with Slim Profile Design. The alarm is half the depth of a standard alarm and provides reliable 2-in-1 smoke and carbon monoxide protection. Meets new industry standards with First Alert's Precision Detection advanced sensing technology. First Alert's Precision Detection advanced sensing technology complies with new industry standards to reduce cooking nuisance alarms and provides early warning in the event of a home fire emergency.