The detector uses an advanced electrochemical carbon monoxide sensor to accurately detect carbon monoxide levels regardless of its location in the room. Despite its small size, it offers strong conservation. Features: Carbon Monoxide Excessive Concentration Alarm: The use of coal stoves for heating and cooking in sealed rooms, closed doors and Windows without ventilation measures to provide insufficient oxygen can produce large amounts of carbon monoxide gas and cause indoor poisoning. The LCD Screen Displays the CO Concentration: The number clearly shows the gas concentration to understand the leakage situation. Low Battery Warning: When the power supply drops to 3V, the buzzer will display a red flash every 20 seconds. After repeated alarm 15 times, the unit will stop working. Loud Sound and Light Alarm: 85dB high-pitched alarm precision alarm safety guard to prevent disaster. Alarm Standard: The alert time depend the level of carbon monoxide concentration. 50ppm, alert within 60~90 minutes; 100ppm, alert within 10~40 minutes; 300ppm, alert within 3 minutes. (Note: When you test the detector, please do not use gas blow the hole directly.) Specifications: Material: ABS Power Supply: 3PCS AAA 1.5V (Not included) Sensor Type: Electrochemical Type of Gas Sensed: Carbon monoxide Detecting Level Range: 000~999PPM Sensitivity & Time: 50ppm, alarms within 60~90 minutes 100ppm, alarms within 10~40 minutes 300ppm, alarm within 3 minutes Standby Current: 50uA Alarm Current: 75mA Operation Ambient Condition: -5~40, 20~90%RH Horn Level: 85dB at 1M Item Size: 78 * 48 * 25mm / 3.07 * 1.88 * 0.98in Item Weight: 55g / 1.94oz Package Weight: 87g / 3.06oz Package Size: 10.5 * 10.5 * 3.5cm / 4.13 * 4.13 * 1.37in Package List: 1 * Carbon Monoxide Detector 2 * Screws 2 * Anchor Plugs 1 * User Manual (English)