SITERWELL Smoke Detector, 10-Year Fire Alarm Smoke Detector with Built-in 3V Battery and Photoelectric Technology, Fire Detector with Low Battery Warning and Silence Function, UL217, GS508C, 4 Packs

【Activate before Installation】 Press and hold the test button for 3 seconds until the LED light is released within 2 seconds, and the smoke detector will generate “beep”, indicating successful activation. If activation fails, the smoke alarm won’t work
【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
【Easy Installation&High Quality】The fire detector will also be easily installed through the mounting bracket. It may be easily mounted on the wall or ceiling. Our products are UL certified, so you’ll be able to rest assured and absolutely accept as true with our products
【10 Years Battery】The smoke alarm has a built-in 3V lithium battery, which runs for 10 years and reminds you when the battery is low. When the alarm sends a fault signal, you should replace the product straight away
【Photoelectric Technology】The smoke alarm adopts photoelectric technology. Before spraying into the flame, it’s more sensitive to detect slow fire. The fire point is in most cases thick, and the black smoke may turn into thinner for several hours