Early warning of an unexpected fire: The TÜV-tested smoke detector, photoelectric sensor. The device responds quickly to the onset of smoldering fire, emits a loud and penetrating alarm above 85 dB. Help people spot the fire in time, escape safely and reduce property loss, an important protection device for life and property. 2.4 GHz WiFi is required when connecting the smoke detector to the app. Indoor use: Ideal for bedrooms, living rooms, hallways, etc. The LED indicator flashes every minute to let you know the fire alarm is working well, and a dim green light will not disturb you to sleep at night. attractive look and ultra thin. diameter : 120mm, height: 31.5mm. The small fire alarm is not obvious on your white ceiling, has no influence on your beautiful home decoration. Silent Mode: After the smoke detector detects smoke and alarm goes off, you can turn off the alarm for 10 minutes by pressing the power button (in the center of the lid). The detector will return to normal working mode after 10 minutes. Long life: the smoke detector is equipped with a 10-year lithium battery (not replaceable). You don't need to go upstairs to remove the fire alarm any more to change the battery from time to time. Easy Installation: There are screw kits and double-sided tape in the package. To drill or not to drill. Please select the best way to install the fire detector according to the mounted locations. We recommend installing with screw kits. Solid and once and for all. Please watch the video and read the user manual carefully when you receive the smoke detector. It can help you operate the fire alarm easily and correctly. Note: The data is manual measurement, please allow 1-14cm error, due to differences between the light and screen, there will be a certain color difference, the specific received in kind prevail.