Features: A loud alarm will be triggered and push instant notification to your phone immediately when someone opens or close your door or window, making you informed all the time. Provides 24-hour monitoring. Even if you are far away from your home, garage, garden, etc., you can check whether the door/window is open or not with the app anytime and anywhere. Support checking open/close records in-app. Never worry about missing any important moment. If you install more than one door sensor in different places. All the statuses of doors and windows will be displayed simultaneously within the app so that you can easily know what you want briefly. When the battery level is low, it will automatically remind you to change the battery, and never worry about running out of battery. Share the added door sensors with your family member, they also can monitor the status of your doors/windows when you are outside. Convenient for you to detect your doors, windows, cabinets, drawers, or anywhere you want to be notified when it is opened or closed. When you leave home, it will push a notification message to you when the door/window opens or closes, so you can discover the intruder in time. No complicated installation tools are required. Protect your home and families. When power is low, the sensor will push messages to remind the user to replace batteries in time. Two Status: Open & Close Battery: 2 * 1.5V AAA Batteries (Not Included) Standby Current: ≤5μA Protocol: IEEE 802.11b/g/n Wireless Range: 50m