?10-Year Product Life?The smoke alarm has 1-year 9V battery. This smoke alarm can be used for ten years with continuous battery replacement. Working smoke detector cut the risk of dying in a home fire by 50% while a home fire starts every 83 seconds! The faster you realize a fire warning, the more time to escape from the fire | ?Photoelectric Technology?The GS509A is a photoelectric smoke alarm. The photoelectric technology, it is more sensitive in detecting slow smoldering fires which generate light smoke, little heat and may smolder for hours before bursting into flames | ?Test/Mute Button?The smoke alarm is designed to test the normal operation of the product by pressing the test button. Weekly testing is required. The product is designed to be silent and not disturb your rest | ?Humanized Design?Loud>85dB makes everyone in the house can hear the alarm clearly when the smoke alarm is chirping. If low battery there will be a signal alarm, which informs you to change a new battery | ?Easy Installation&High Quality?The fire detector can be easily installed through the mounting bracket. It can be easily mounted on the wall or ceiling. this equipment is installed in accordance with the NFPA standard 72, so you can rest assured and absolutely trust our products.