The AXIS Kiteboarding 18mm kiteboard fin set includes 4 x 18mm colored solid Premium G10 fins. G10 is the strongest material for kiteboarding twin tip board fins. The fins are secured by 8 x stainless M6 x 16mm screws through from the deck with our own fin retainers. The retainers spread the load from the screws to the deck area. The AXIS 18mm fins are designed for wake style boards, and make a board really skatey. Ideal for boot riders and wakestyle boards such as the AXIS Bootleg , the AXIS Billy, and the AXIS Tranq .