High-sensitivity sensor: Best carbon monoxide alarm for real-time monitoring and accurate alarm. It is a must-have for old residential areas, families using gas water heaters/coal stoves, newly renovated houses 3-mode reminder: The portable carbon monoxide detector digital has a large screen display + LED flashing + car horn-like sound alarm, which is an excellent travel carbon monoxide detector for hotel room. Even in sleep, you can be awakened by the alarm sound Easy installation & battery-powered: Battery-powered carbon monoxide detectors do not require wiring and are ready to use, suitable for homes, apartments, offices, RVs and other scenarios Auto Self-Test - Weekly checks & low-battery alerts: When the yellow indicator light of the co detector flashes, you need to replace the battery, and this process repeats every 60 seconds 365-Day Limited Warranty: CCCF fire certification, Uninterrupted 24/7 protection. Comes with instruction manual to ensure correct use. Please note the color change of the indicator light UPC 766757412373 Size 3 pack Brand Uingarm Color white Unit Count 3.0 Count Item Weight 0.6 Kilograms Manufacturer Siterwell Electronics Co., Limited Model Number ‎GS888A Power Source Battery Powered Audible Noise 90 Decibels BuiltIn Media 02 Control Method Push Button Mfr Part Number 01 Sensor Technology Electrochemical Battery Description Alkaline Number of Batteries 3 AA batteries required. (included) Smart Home Compatibility Not Smart Home Compatible Item Dimensions L x W x H 16.5 L x 3.7 W x 16.5 H