Twoway search function: It is connected to the Bluetooth function of the mobile phone click click alarm in the APP it will make a sound and find through the sound. Doubleclick the button to make the phone beep and you can find the phone. Disconnection alarm function: in the connected state when it exceeds the set Bluetooth range both will alarm at the same time (use this function the soft switch of disconnect alarm must be turned on in the APP settings). Positioning break point function: On the mobile APP you can check the map positioning when the antilost device is disconnected. It does not have the tracking and positioning function and only supports historical record positioning. Remote Selfie function: You can use the mobile phone APP to take pictures remotely by clicking the button of the antilost device. Recording function: When the antilost device is connected the mobile phone recording function can be controlled through the antilost device (the doubleclick recording soft switch must be set in the APP).