Share music anywhere with Goal Zero’s rock out speaker, with its smallest and most light weight solar panel, so you can share music anytime anywhere. The rock out mobile kit includes the rock out portable speaker with the Nomad 3.5 solar panel. The rock out speaker plays music for about 20 hours on one charge, and can be recharged from the USB port on the Nomad 3.5 solar panel. Recharge your MP3 player from the Nomad 3.5 solar panel as well. Most small USB devices can also be charged straight from the Nomad 3.5, like a cell phone.