The Edge fins are speed training fins, engineered to do it all, and designed to optimize training without interrupting a natural kick cycle or compromising on comfort. The Edge fins are speed training fins, engineered to do it all, and designed to optimize training without interrupting a natural kick cycle or compromising on comfort. Designed to catch water on the up-kick, activating hamstrings and glutes 100% Silicone for optimum performance and comfort Increased surface area and reinforced side rails for a proper kick at high speeds Ergonomic contours maintain constant connection with the top of the foot to prevent skin irritation and tension