The Jam Transit Ultra gives you complete freedom of movement while you listen to your music. The Bluetooth earbuds are totally wireless, meaning there are no annoying wires dangling around your body or in your face. A fully charged battery gives you 3 hours of uninterrupted listening to your favorite songs. When the earbuds' batteries are empty, they can be charged with the portable power bank. This charger gives the Ultra 30 hours of extra battery life. The design of the earbuds is both sweat and splash proof. This means you can use them when exercising in the rain, without any problems. If you're called when listening to music, you can use the integrated microphone to call hands free.Note:always download the latest software update of the app to prevent user problems and to make optimal use of the earbuds.