The REGEN is a battery less MP3 player. You are now asking... how does it get it's power? Of course you use it as a yo-yo to give it the power you need to listen to MP3's. It can store up to 200 songs on it's harddrive and has a touch screen LCD which you can select your music to play.
Expect to have to yo-yo around 10 - 12 throws to get enough power to use the device. The headphones are bluetooth so there is no worries about your yo-yo pulling them out of your ears.
