Check the listing for details. FCS II H4 Thruster Tri Fin Set - Size Medium. Condition: New. Listed at 160.00 USD. The H4 looks and surfs different to any other fin. Precision Swiss engineering matched with a highly evolved template provides an unprecedented level of control and predictability at high speeds. This is a 3 fin thruster fin set in size medium with a five star review on FCS. Radically different side & center fin templates create a powerful fin set with ultimate speed & drive. Side Fin Profile: Lower section produces maximum acceleration, while hatchet like tip creates stability & control. Center Fin Profile: Highly raked elliptical outline reduces drag, and offers feeling of predictability when releasing through turns. Fin Foils Template: Thicker base with tapered tip optimizes flex & regulates the release of energy during rail to rail transitions. Ideal Conditions: A wide range of conditions, particularly good in critical overhead waves. Board Types: Designed to fit the FCS II Fin System. Recommended for performance shortboards with moderate-to-low rocker. Fin Family: Accelerator: Find Control. Speed, flow and response with added control.