The Jam Ultra are wireless earbuds. By removing the cable between the two earphones, you no longer have any restrictions in your movement. The Jam Ultra comes in a charging case which, in addition to being a handy storage case, is also an extra battery. This gives the earbuds a maximum battery life of 21 hours. The built-in microphone makes it easy to make hands-free calls. In addition to daily use, the Jam Ultra is also very handy for athletes due to the sweat-resistant design. True wireless The Jam Ultra are earbuds that are completely wireless. With most âwirelessâ earbuds, there is still a cable between the two earphones. This has been removed from the Jam Ultra. This will no longer restrict your freedom of movement. With the earphones you can also answer phone calls immediately. Charging case The earbuds come in a charging case. This storage case is also your charger. This extends the battery life from 3 to 21 hours. When your earbuds still have enough battery but your phone starts to run dangerously empty, you can also charge your smartphone via the USB connection. Also for athletes The Jam Ultra is also very handy for athletes. The completely wireless design ensures 100% freedom of movement. The earbuds are also sweat-resistant, and with a 3-hour battery, they'll last long enough for almost any workout. Â Â