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 10 Year Battery Model 4-Pack

【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 will not 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 can be easily installed through the mounting bracket. It can be easily mounted on the wall or ceiling. Our products are UL certified, so you can rest assured and absolutely trust 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 must replace the product immediately
【Photoelectric Technology】The smoke alarm adopts photoelectric technology. Before spraying into the flame, it is more sensitive to detect slow fire. The fire point is generally thick, and the black smoke may become thinner for several hours