Universal Smart Bluetooth Tag Locator - Bluetooth 4.0, 200mAh - 52mm x 31mm x 11mm Use the intelligent Bluetooth tag locator if you have a problem with losing your things. This little tag item tracker contains a designed hole so that you can hang it on keys, belts, and luggage, and it adds no bulk to your essentials. If you’re wondering how it works, activate the tag sound via a smartphone app, or you can track your connected smartphone by using the button on the tag locator. If the tag locator is out of range, the app will automatically start recording the GPS position.