Smart Contact SensorTapo T110 Window/Door Safeguard - Monitors the opening & closing of windows, doors, cabinets, the fridge, or the mailbox in real time.Instant App Notification - Is your parcel locked away? Find out immediately with instant notifications.Smart Action Support - Connect the actions with other smart devices for a welcome return home.Easy Installation - Mount to nearly any surface with included 3M adhesive.Great Compatibility - Just one part of the integrated Tapo ecosystem.SYSTEMHub Required: YesHARDWAREIndicator LED: YesTECHNICAL SPECIFICATIONSWireless: 868 / 922 MHzGENERALOperating Temperature: 0~40°CDimensions( H X W X D ): 61.4 x 37.5 x 12.3 mmPower Requirements: CR2032 BatteryPACKAGE CONTENTSTapo T110Quick Start GuideBattery CR2032 x 13M adhensiveENVIRONMENTOperating Temperature: 0~40°C