\"The Code One Battery Powered Combination Smoke & Carbon Monoxide Detector， is an alarm combo that operates on 2 AA alkaline batteries (included). Battery-operated smoke detectors provide protection during power failures for extra peace of mind. The Code One Smoke & Carbon Monoxide alarm is equipped with a self-testing component that is always checking the unit to ensure the device is operating as expected*. Included with your smoke alarm & carbon monoxide detector is an easy-install mounting bracket that provides simple， quick installations in 4 orientations. The Code One smoke alarm uses a photoelectric sensor that detects visible fire particles associated with slow smoldering fires， as opposed to an ionization sensor， which can be better at detecting less-visible fire particles from fast flaming fires and uses an electrochemical carbon monoxide sensor， which offers accurate readings of CO. When this combination smoke and carbon monoxide detector senses a smoke or CO hazard， a loud 85-decibel alarm will sound. The alarm will also begin to chirp when the battery is nearing the end of its life， so that you know when it needs replacement. Place a smoke detector and carbon monoxide detector on each level of your home and inside and outside each bedroom. UL Certified with a 10-year limited warranty. Meets requirements of UL 2034， UL217， NFPA72， NFPA 101， FHA， & HUD.

2-in-1 Detection - Smoke detector-carbon monoxide detector combo alerts you to both smoke and CO in a single unit

Easy Installation - mounting bracket included for quick installation

Self-Testing - Smoke and carbon monoxide detector uses internal， self-testing components that are always checking to ensure the device is operating as expected (not a substitute for weekly manual testing)

Photoelectric smoke sensor detects visible fire particles associate with slow， smoldering fires sooner than an ionization sensor

Electrochemical sensor detects carbon monoxide & remains stable during humidity changes & unstable temperatures

2-AA alkaline batteries power the detector

One-Touch button activates the Hush feature to temporarily silence nuisance alarms， tests the detector's electronics & verifies proper operation， & silences low battery chirp for up to 24 hours， maximum of 7 days

End of life chirp alerts user to replace the smoke detector-carbon monoxide detector combo after 10 years of operation

An 85-decibel alarm will sound when the smoke and CO alarm senses a smoke or carbon monoxide hazard

UL Certified with a 10-year limited warranty

UL/CSFM Ref. Kidde Part KN-COSM-XTR-BA