No wires mean no limits. And Bose sound sport free headphones are completely wireless, so you can enjoy total freedom of movement with nothing-not even a single cord-in your way. The acoustic package is designed to deliver sound so clear and powerful it will motivate you to go faster, lift heavier and train longer. Bluetooth technology transmits music from your phone to the headphones, so music plays reliably and consistently whether your phone is in your nearby gym bag, pocket or strapped to your arm. Worried your earbuds will fall out during your workout? don't be. Stay hear+ sport tips are built to stay comfortably in place, even when you're training hard. And if you can't find an earbud, all hope is not lost. You can track down lost earbuds using the Bose connect app's “find my buds” feature.