It is a fire smoke detector alarm, general purpose ideal for all areas : house, shop, hotel, restaurant, office building, school, bank, library, computer house and storehouse etc. Alert and warn people stay far away from danger field when it detected smoke. The detector adopts the special structure design and ASIC, has the dustproof, mothproof and anti outside light interference feature etc. Alarm test button Description: This smoke detector detects the smoke to make sure everyone is awakened and alerted in case of a fire emergency.The detector is suitable for detecting the smoke in home, room, shop, hotel, restaurant, office, school, bank, library, computer house, storehouse and etc Easy to install Photoelectric sensor for early detection from all directions Specifications: Alarm volume: 10 feet to 85 dB Round Size: R = 102mm, H = 31mm Powered by DC9V battery (Not Included) Usage: Fire, Smoke Model Number: family guard Is customized:no Packing content: 1 x Smoke Alarm 2 x screws Notice 1. Please allowed 1-5mm differences due to manual measurement, thanks. 2. Due to the difference between different monitors, the picture may not reflect the actual color of the item.