Dahua Alarm Wireless Standalone Carbon Monoxide Detector HY-GC20B High-performance Figaro electrochemical CO sensor to deliver accurate detection of carbon monoxide leakage and respond quickly Long standby time, low power consumption, 10-year battery life Support low battery warning, one-click silence, and self-test Informative and easy-to-read CO concentration display in screen Three indicator lights for displaying device status clearly Excellent production, novel appearance, delicate and compact, simple and convenient installation Working Principle Collection Type : Carbon Monoxide (CO) Sensor Type : Electrochemical Alarm Alarm Type : CO alarm, fault alarm, low battery warning Alarm Volume : Over 85dB (A) at 3 m (9.84 ft) Alarm Mode : Visual and audible alarm Silence Function : Support Silence Duration : About 45 seconds Alarm Response Threshold : 50 ppm: 60 min–90 min / 100 ppm: 10 min–40 min / 300 ppm: < 3 min Basic Parameters Display : LCD Indicator Light : LED (red/yellow/green) LED Instruction : Alarm: Red indicator / Fault: Yellow indicator / Power: Green indicator Power Supply  Battery Life : 10 years Power Source : 3V CR123A lithium battery (replaceable) Operating Current : Monitoring Current: ≤20uA / Alarm Current: ≤10mA Operating Ambient Operating Environment : Indoor use only Operating Temperature : –10°C to +40°C (+14°F to +104°F) Operating Humidity : ≤95% RH (non condensing) Appearance  Color : White Materia : PC + ABS Dimensions : 116.4 mm × 71.7 mm × 28.3 mm Weight : 125 g Installation : Wall Mount Certification Certifications : TÜV and CE listed Compliance Standard : EN 50291-1:2018