The gentle curves allow the Curved Hexes to cam into position by rotating on the convex face and setting up a triangulations with the concave side, it also allows them to slide past nubbins and irregularities that would block a traditional Hex.ex * They are incredibly lightweight (extruded 6061 - T6 Al) and about 1/5 the price of quality camming units. * Color coded tubing makes identification easy.