Product Features: 1. Instant Notification: Push instant notification to your phone immediately when door or window is opened or closed. Keeping you informed all the time. 2. Alarm Alert: Whenever the sensor is triggered to open/close, it will send alarm to alert you that someone opens your door or window. 3. Alarm Recording: Support checking open / close records and battery level on the app. Never worry about missing any important moments or running out of battery. 4. Device Share: Select "Home Management" in the "Me" page to share your added sensors with family members. so that they can also monitor the status of doors/. 5. Low Voltage Remind: When battery level is low, it will automatically remind you to change batteries, never worry about running out of battery. 6. Works with and Assistant. Colour: Black Material: ABS Package Contents: 1 x Main Body 1 x Small Body 1 x glue 1 x English User Manua 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.