I've seen that one before, but yeah, it is brilliant, basically two "screw" pontoons, cutting a thread in the snow to pull the vehicle along. I've seen a similar set up on "Junkyard Wars" Don, where they built an amphibious vehicle with the same technology, just bigger "screw" pontoons. It'd be a lot slower than a tracked snowmobile, but for big loads, it'd be excellent! Cheers, Terry.