It's a YoTank case - I got mine on eBay but there doesn't appear to be any up at the moment. It was about $70 shipped - the thing is indestructible! It's pretty heavy, though.. which isn't a big deal to me but might for some people. I had to modify my car dock to hold the case and a FiiO amp.
I've seen a bunch of people on here using these YoTank cases actually.