Provides 24-hour monitoring When the battery level is low, it will automatically remind you to change battery, never worry about running out of battery. Push instant notification to your phone immediately when door/window is opened or closed Loud alarm will be triggered when someone open or close your door or window, make you informed all the time. Share the added door sensors with your family member, they also can monitor the status of your doors/windows when you are outside. SPECIFICATION 1)Push instant notification to your phone immediately when door/window is opened or closed. so you don' have to worry about your baby going out of house without notice, will know when your aged parents leave or arrive home and even can be clear when someone enters your home,shop,office ,etc. 2)Provides 24-hour monitoring. Even you are far from your home,garage and garden,etc, you can check whether the door/window is open or not with app anytime and anywhere. Szkoston 3)Loud alarm will be triggered when someone open or close your door or window, make you informed all the time. 4)Support checking open / close records in app.Never worry about missing any important moment .If you install more than one door sensor in different . All the statuses of doors and windows will be displayed simultaneously within the app ,so that you can know what you want at a glance. 5)When the battery level is low, it will automatically remind you to change battery, never worry about running out of battery. 6)Share the added door sensors with your family member, they also can monitor the status of your doors/windows when you are outside. Colour:White Material:ABS Size:7 x 4 x 2cm Package Contents: 3 x siren (Need 2 x AAA batteries no include) 3 x magnetic stripe 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.