The Bang & Olufsen BeoPlay E8 earbuds are completely wireless. This way, cables won't get in the way and you'll have freedom of movement. The earbuds use Bluetooth and last for up to 4 hours on 1 battery charge. The portable charger allows you to fully charge your earbuds 2 times. You can control your music with the buttons on the earbuds' touchpad. By tapping 1 time, for instance, you can accept incoming calls or pause your music. A set of 4 sleeve sizes is included. If you use the right size, the earbuds won't fall out of your ears.Note: please make sure to always download the latest software update of the app to prevent problems and to ensure you're getting the most out of the earbuds.