The product description from Amazon is wrong to it are called functions are not available:
"The charge of the internal battery via a USB cable (included Lieferumfanf). At the same port, you can also use the included audio cable with 3.5mm jack mount, which allows you to operate your music player even without Bluetooth."
It is said cable supplied with 3,5 mm jack and there is this possibility according to the manufacturer not in this model (AKG K840 KL offers this possibility, for example).
