The smart connected smoke detector with built-in lithium battery lasts for 10 years. You will never have to replace the batteries in your smoke detector. Photoelectric sensors more effectively detect smoke from slow-burning fires, such as smoldering materials Smoke alarms are less sensitive to alarms caused by cooking fumes or . With the included screw mount and guide, you can quickly and easily install the smoke detector securely Always stay up-to-date on what's happening in your home with connected smart smoke alarms Colour:White Material:ABS Size:12 x 12 x 3cm Package Contents: 1 x fire alarm 1 x screw pack Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.