The new Thor fin has a peculiar and unprecedented structure that combines the two central ribs in high modulus polypropylene, very reactive and a central area of the thermoplastic rubber with a convex section, assembled in a polypropylene blade. Two lateral nozzles, located in the area where the flexion starts, release the associated negative forces and allow the use of two high-response ribs. This combination causes a channeling and acceleration of water flow, which stabilizes and increases propulsion at equal effort. The inclination of the blade with respect to the foot pocket has increased by 5% compared to traditional diving models. This angulation provides greater efficiency and a more natural foot position during fluttering. Thor enjoys the exclusive 3-material injection system patented by Cressi, which provides an excellent combination of strength, power, comfort and aesthetics and the optimization of the requirements of each area of the fin