Your Personal Housekeeper&Receptionist: Instant notification to your phone immediately when door or window is opened or closed. As a result, you don't have to worry about your baby going out of house without notice, easily know when your aged parents leave or arrive home and even can be clear when someone enters your shop, office and company reception, etc. Keeping you safe and informed all the time. Full Peace of Mind: door sensor provides 24-hour monitoring. Even you are far from your home, garage, car, shed, and garden, etc, anytime and anywhere. No need to be concerned about whether you have forgotten to close door/window and whether someone breaks into. Everything is Under Control: Support checking unlock/ lock records and battery level on free Smart Life app. Never worry about missing any important moment or running out of battery. If you install more than one door sensor in different places. All the statuses of doors and be displayed simultaneously within the app so that you can easily know what you want at a glance. Share with Family: Share door sensor with family menber via free Smart Life app, which means everything be shared, even including sense of security. No need cumbersome installation tools. Colour:White Material:ABS Due to different product batches, the appearance , which does not affect the use Package Contents: 3 * Door Sensor 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. Have a great time shopping!