Well, if you look at one closed, you see the where the blades are in the front, by the tip? That straight line across...Wish I had a pic, but I don't....anyway.....when those hit hide, the blades push back, toward the fletching and away from the deer, and slide out to open. When they get to the deer, they're fully deployed.

This is the reason I don't think Rage burn up as much KE when they enter a deer. In that respect, they are very similar to a fixed blade head.