FCS II MR PC XLarge Tri Retail Fins Dusty BlueOverview Mark Richard's famous twin template produces exceptional drive and speed. The small stabilizer (centre fin) adds control whilst maintaining the freedom and manoeuvrability of a twin fin set up. Board Types Designed to fit the FCS II Fin System. Recommended for all board types including fish, funboard and twin fin boards. Performance Core Performance Core (PC) fins are made using a multi layered resin transfer molding process. The flex pattern