This easy-to-install carbon monoxide detector features photoelectric smoke sensor and electrochemical CO sensing technology. It comes with an LCD display that shows real-time CO concentration and battery life, and gives an 80dB alarm decibel when the levels rise. With easy test button and convenient mounting bracket, it helps minimize false alarms and is perfect for home use. Requires 3 AA batteries (not included). Features 1. 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). Specification Material: ABS Color: White Size: 11 x 11 x 4 cm Weight: 100 g, 200 g Battery: 3 AA Batteries(Not Include) Working temperature: -20 C ~ +50 C Alarm decibel 80dB Package Include: 1 Carbon Detector or 2 Carbon Detectors