The green Rock Out 2 Wireless Rechargeable Speaker from Goal Zero is a weatherproof, rechargeable, and wireless speaker with a built-in mic. It can be charged using a Goal Zero solar panel (using the Nomad 7 solar panel takes about 2-4 hours), or it can be charged from any USB source in about 2 hours.
DarkBass chamber allows massive airflow for deep, precise sound without the bulk
Built-in mic doubles as a rugged speakerphone and can answer incoming calls
Bluetooth connectivity lets you listen untethered
Use the elastic cord to attach the speaker to your pack or ride