[CO & Smoke Combination Detector] With advanced electrochemical carbon monoxide sensor and photoelectric sensor, the detection of CO and smoke are accurate. [LED Flash and Loud Alarm Pattern Warning] When dangerous smoke or CO concentration is detected, it will warn you with LED flashes and loud alarm pattern sound. [LED Display Screen] Can clearly indicate real-time carbon monoxide concentration in the surrounding air. [Battery Power Supply] Powered by 2 * AAA (not included), no need to charge, no messy wires, convenient to use. [Easy to Install] Comes with one bag of screws, easy to install the detector on walls of bedroom, living room, kitchen, etc. Specifications Color: White Material: ABS Detection Gas Type: CO, smoke Alarm Mode: Flash + loud alarm pattern sound CO Sensor Type: Electrochemical Working Temperature: -10~60 Relative Humidity: 10~95%R.H. CO Sensitivity: 000-999 PPM Alarm Sound: 75dB (1 meter) Alarm Concentration: 50ppm: Screen light up, 150ppm human voice alarm Power Supply: DC 3V, 2 * AAA batteries (not included) Product Size: 6 * 6 * 2.5cm/ 2.3 * 2.3 * 0.98inch Product Weight: 70g/ 2.4oz Note Batteries are not included. Package List 1 * Detector 1 * Bag of Screws 1 * User Manual