The grinds have a grind plate right under where your boot is. Basically they make the edges go into the ski and it has a plastic edge to grind on. Tough to explain but if you are looking at the bottom of the ski the metal edge has an hour glass shape getting narrower under the boot. The only problem i have found is the plastic or whatever material makes up the edge under your boot is already starting to peel away after using them three times. Not bad though. Can always warranty them.
Where did you find it?
I don't know. I was too excited. We're in the Lesbian stronghold