Back in January the folks at Phoenix-Fly dropped an incredible video of wingsuit basejumpers doing their thing in the European Alps. If you're not familiar with so-called "squirrel-suit flyers," these guys leap off cliffs and reach speeds of over 100 miles per hour, soaring just above the treeline of a craggy mountain face. In other words, anyone who does this for kicks has balls made of pure titanium. Check out the high-octane video after the jump.