A combination of the exclusive and patented OPB and Channel Thrust systems, for a full-foot fin that fears no rivals. High performance with minimal exertion, maximum comfort and exceptional light weight - a combination that makes diving more enjoyable. Orthopedic foot pocket in soft thermoplastic rubber for maximum efficiency and unparalleled comfort. OPB (Optimized Pivoting Blade) system with expandable inserts for controlling and optimizing the thrust angle. Channel Thrust Technology for perfect routing of the water flow. Rubber covered stabilizers and ribs, provide improved performance.