It comes with an adapter for USB connection (if needed). A simple concave hole would have sufficed. We ordered these in a 13 and they fit like a 12. I was looking for simple headphones for work to drown out the chatter, lol. The Classics are quite a bit boxier and wider in width than the Freesail and the Classics seem to have a bit more cushioning on the bottom. This Blu-Ray player is not a Bluetooth Built-in Blu-Ray Player. I clip the biner end to the boat cleats and can place the loop end over the dock cleat. The aura wins on Volume and fantastic base but you give up the portability of size and battery operation. Hard to install. Shame on me for buying a lesser brand and expecting a usable product.