We use this to charge our Bluetooth headphones and smartphones. This is an ingenious design. A portion remains directly in the headphone jack. The magnetic end of the cable is easy and straightforward to attach. The connection is strong. The lifespan of the cable is better than being stuck in device chargers. I can use this on any device except devices that come packaged in protective cases with a cover over the slot. The kit includes three types of connectors for devices of different sizes.