Features1. Carbon Monoxide Detector: Features electrochemical Carbon Monoxide sensing technology and photoelectric smoke sensor optimized to detect larger smoke particles produced by smoldering fires; helps minimize the number of false alarms.2. Test button: press it for a few seconds to give an audible alarm indicating that the alarm is normal.3. LCD Display: Clearly indicates real-time carbon monoxide concentration in the surrounding air as well as the remaining battery life, and working status of the alarm.4. Easy Install and Use: The alarm can easily install with mounting bracket. No hardwired anymore, very convenient to install at home or bedroom-wall.5. A loud 80-decibel alarm sounds when Carbon Monoxide, and Smoke levels begin to rise. Power supply: 3 AA batteries (Not Included Battery).SpecificationMaterial: ABSColor: WhiteSize: 11 x 11 x 4 cmWeight: 100 g, 200 gBattery: 3 AA Batteries(Not Include)Working temperature: -20 C ~ +50 CAlarm decibel 80dBPackage Include:1 Carbon Detectoror2 Carbon Detectors