The Chipolo ONE Bluetooth Tracker helps you locate individual items by connecting the tag to the Chipolo app. The tag can be placed in a small pocket or clipped onto something via the built-in hole. With the app you can ring the Chipolo ONE, you can track where you had it last, and you can be alerted if you leave without the item it's attached to. You can also double-click the Chipolo ONE itself to ring your phone.