TORELLI Serpent HARD Cabonfibre blades recommended for divers >85kg range or smaller fit divers. They are a pure carbon fibre fin blades produced by double sided vacuum infusion process ensuring that there is no trapped air in carbon fibre sheet plies. Specially formulated epoxy resin is used for impregnating the carbon fibre. The parabolic flexing curvature is achieved by careful material placement and fibre orientation. Fins designed this way will give you more thrust for longer and deeper dives.