Window/ Door Safeguard – Monitor the opening and closing of windows, doors, cabinets, the fridge, or the mailbox in real time; perfect as a window alarm ; door alarm ; shed Real-Time Notifications – Trigger Hub alarm (Tapo Hub required and purchased seperately to activate smart alarm) and send you notifications via Tapo app whenever doors/windows are open; Tapo door sensor alarm improve your home security Smart Actions Support – Connect the actions with other smart devices whenever doors/windows are open for security or home automation Battery Powered – Battery-powered design with 1+ year battery life; Tapo smart contact sensor is a perfect solution to your home alarm systems Easy Installation and setup – Mount to nearly any surface with included 3M adhesive, Set up quickly and easily through the free Tapo app This device operates exclusively within the specified Sub-1G band; Please note that different regions support different frequency bands; Ensure that the devices or hubs you intend to use are compatible with the same Sub-1G band