1、Trigger your alarm and get notified when a door or window is opened, very timely. 2、Check the status of the door/window opening and closing in real time, and the on‑off record is clear at a glance. 3、Independent use, without host/gateway, simplifying complexity. Exquisite and stylish appearance, fit for various environments. 4、Ultra‑low power consumption and long battery life, energy‑saving and more practical. 5、Completely wireless with user-replaceable battery. The product has the door opening, closing, battery power display. Item Type: Door/Window Sensor Material: ABS Color: White Size: Approx. 76x31x20mm / 3.0x1.2x0.8in Weight: Approx.51g/1.8oz Battery: 1 x CR2 lithium battery(Built-in) Battery Capacity: 850 mAh Application: Check the status of the door/window opening and closing in real time, and the on-off record is clear at a glance. 1 x Door/Window Sensor 1 x Magnetic Strip 1 x Sticker 1 x Pin 1 x English Manual