Wavegrinder Shortboard Fin, Large Wavegrinder's shortboard surfboard fin with winglets is the first size of several to come, is designed to give lots of hold for its size. Although this fin is the size of typical medium thruster fin, it produces a lot more hold/lift than a typical medium sized fin. Fits FCS boxes. 14.58 square inches in area (13.58 in the fin, 1 in the winglets). 5.65 inches tall, deep. Made with Lexan polycarbonate, the same stuff used in bulletproof glass and fighter-jet canopies.