The new Aerial7 Sound Disk Beanie features built in headphones with a 35mm driver diameter for big sound in a small package. Plus, the headphones are multi-device compatible and have a sleek in-line microphone that works with the iPhone and other mobile devices. It hits stores globally on December 1st, and if you can’t wait there’s an early drop on Aerial7′s website come November 15th. The Sound Disk Beanie retails for $59.99 (USD). See that special Beanie worn by Heikki Sorsa in the gallery below.