You can plug it into a jack (cable supplied) to a USB stick or an SD card.
When the cable is connected, take precedence over the other and cut.
The most convenient is to put music on an SD card, as it shortly after connecting the GPS to the USB socket for charging.
There is a rather remote practice.
The only downside is the firmware, software. It is very rough with the information (tags) to music, see the pits at that level. It will therefore create faloir record of 8 characters to be able to navigate.
Too bad the rest is very good.
I however am not disappointed with the purchase, we adapted to the poverty of the internal software. And it will always be the cable to jack with the ability to recharge the player on the USB plug.