Details Features - 1.SMALL BUT ACCURATE - The smoke alarm adopts photoelectric technology to detect smoke. More sensitive to light smoke and slow smoldering fires and more quickly to remind you. Keep your home safe. 2.EASY INSTALLATION - The fire alarm can easily install with mounting bracket. No hardwired anymore and you can install it wherever you want. 3.Sound & LED Warning - When the fire alarm detects smoke or detect combustion particles in the air, it will sound their alarms and the red LED will flash rapidly to remind you to check. Specifications - Power Supply - Battery Operated (batteries not included) Sensor Type - Smoke Detector Installation - Ceiling or Wall Mount Recommended Distance - Install at least 2 meters above gas sources Packing Include - 8 x Smoke Alarm16 x Screws Important Notices - Batteries are not included. This device detects only smoke concentration, not carbon monoxide (CO). This version cannot connect to mobile phone software. Do not install near gas sources or in damp places (bathroom/shower).