Bluetooth Loss Alert Dongle for Mobile Devices Very small in size, and can be used as key chain dongle Over distance alarm for your smartphones or tablets. If distance between your device & this bluetooth dongle is over the pre-set limit, it will immediate give you warning via vibration, beeping sound and LED flashing light Indication of incoming phone calls by vibration and LED flash light One key operation, easy to cancel current vibration, beeping or LED flashing light Distance of alert action can be adjusted from 1-meter and up to 10-meter