Product features: 1. High sensitivity: It can quickly and accurately detect tiny smoke particles in the air, and respond promptly even in the early stages of a fire. 2. Sound alarm: When an abnormal situation is detected, a loud sound alarm will be sounded to alert people to potential dangers. 3. Battery powered or hard wired: Supports battery powered for easy installation and maintenance. 4. Easy to install: Designed to be very simple and easy to install, simply follow the instructions in the manual to complete the setup. 5. Long life design: It has a longer working life. Colour: White Alarm Type: Smoke Detectors Features: Battery Operated, Optical Sensor Gas Type: Smoke Room: Bedroom, Living room, Landing Style: Modern Power Source: Battery Features: Resistant to nuisance alarms Package list: Smoke Alarms self-adhesive boards 9V Batteries Notice: 1.The actual color of the project may be slightly different from the picture displayed on the website due to many factors such as the brightness of the display and the brightness of the light. I sincerely hope you can understand. 2.The size is manually measured, and there may be an error of 0-1cm, which is a normal phenomenon.