High-Quality CO Detector: The carbon monoxide detector uses highly accurate and reliable electrochemical carbon monoxide sensors to quickly detect carbon monoxide gas leaks. It can be used in kitchens, bedrooms, etc. Self-Test Function: This carbon monoxide detector features an automatic self-test function to detect hardware errors, which is performed approximately every 1 minute in normal standby mode. User-Replaceable Batteries: The CO detector is powered by three 1.5V AAA alkaline batteries (batteries not included). Easy to install and replace. Dual Alarm: When the carbon monoxide detector detects a dangerous concentration of CO, it emits an audible and visual alarm. 100% Satisfaction: The carbon monoxide detectors comply with EN50291 and have undergone numerous quality tests to ensure your family's safety. Test/Silence Button Press the test button to manually test the CO detector and ensure proper operation. A false alarm can also be triggered by pressing the test button. Low