Accurate & Sensitive: The small size smoke alarm adopts photoelectric technology to detect smoke, which is more sensitive to light smoke and slow smoldering fires and more quickly to remind you. Keep your home safe 24/7 | TEST BUTTON: Please test the fire detector once a month. If red LED flashes with “chirp” every 30 seconds, it's low battery signal, please change battery in 7 days. Small size, DIA 3.3inch. If you have any problem with smoke alarm, please contact us | Easy Installation: The smoke detector can easily install with mounting bracket. No hardwired anymore and you can install it wherever you want, except bathroom and kitchen, keep 3 ft away from the kitchen, bathroom, or other high air flow areas | Sound & LED Warning: When the fire alarm detects smoke or detect combustion particles in the air, it will alert in 85db and the red LED will flash rapidly to remind you to check. If fault, please clean dust or smoke inside smoke alarm with fan | Home Protection: According to US data analysis, a family fire begins every 38 seconds. The faster you know about the fire, the sooner you start moving your family, working fire detector reduces the risk of home fire deaths by 50%