Surfboard Fins M7 - Dual Tab Thruster - CARBON BASESize 7 [= Large Performer] surfer weight 75kg to 105kg fin size: 122mm high 109mm base CARBON Base + Hexcore = Responsive Power Carbon Hexcore fins are the perfect combination of power and response. For those who surf critical, these advanced carbon fins provide a more progressive flex, starting from the stiffer carbon base and releasing through to the responsive fiberglass tip. Meaning you get the best of both worlds, with both power and flex