The lightweight Techflex material and responsive flex pattern continues to be the ideal choice for one of the most progressive, high performance surfers in the world and is now offered in a size that best fits surfers in the large range.--CONSTRUCTION-TECHFLEX-Techflex is stiff like Fiberglass but lighter than Honeycomb. The ultimate in flat foiled fins, great for powerful surfers or powerful surf.--FOIL-FLAT FOIL-Flat foiled fins break free sooner, and are better at controlling speed. Often surfers prefer them in fast powerful surf where they do not need to create additional speed. If you have muscle memory from riding glass-ons, flat foiled fins will feel the closest.