【100% 10 Years Warranty】 : If there are any problems with our products ,you can contact us ,we must reply you within 24hours as soon as possible.NOTE: Please test it once a month to ensure that the smoke alarm works properly. Please clean up the dust on the alarm every 6 months to prevent the smoke alarm from being clogged or blocked. 【Photoelectric Technology&Material】: Fire-Retardant ABS V0 Level. 9V Battery-Powered Photoelectric sensor Smoke Alarm. photoelectric technology which is optimized to detect slow smoldering fires which generate light smoke, little heat and may smolder from all directions for hours before bursting into flames. 【Easy Installation】: Can be installed in several minutes. Coming with screws and bracket. Safety clip feature,not allow mounting of smoke alarm without battery installed 【Sound & LED Warning】: When the fire alarm detects smoke or detect combustion particles in the air it will sound their alarms(Alarm volume: > 85dB(A) @ 3 meters) and the red LED will flash rapidly. The LED light and alarm will continue until the air is cleared or the test button is released. 【Suitable for Multiple Places】: This smoke detector does not contain any radioactive material. It should be installed in every room (except the bathroom and kitchen), making sure the people in your home will be able to hear and respond to the alarm sound.