This door sensor is made of , which can withstand use. Features the ABS and electronic components material, which has high durability, not easy to deform. Fine workmanship, ensures practicality. Features -Color: White -Material: ABS, electronic components -Size: 8.20X5.00X2.50cm/3.22X1.97X0.98in Battery: Accuracy: <5mm - The linkage is automated, closing and and automatically ventilating , the are closed and someone is detected at home, and then the is triggered to work, saving electricity and consumables. - Linked equipment, home lighting, go out early and go home late is the normal life of , go home at night and open the door, the living room lighting will automatically turn on, no need to look for the in the dark. - When the magnetic state of doors and changes, the mobile APP can receive notification pushes in real time, so as to calmly with abnormal situations. - It supports viewing 6 months of historical records, and every time and are opened and closed, there are traces to follow. - It is widely used and from intrusion. It can be installed in any place with monitoring needs such as residences, shops, , hotels, apartments, etc., to protect the site from intrusion. Package list: 4 x pair of window sensors