Old school tinted layer glass in black/blue/white. The Vulcan Flat Four Quads are designed for powerful, on rail surfing. All four fins have a flat inside foil which is the preferred profile for thrust and speed. The most notable feature however is the size of the trailing fin which stands a full 4.5" tall, equal to the height of the forward fins. The result is a massive leap in control and maneuverability. The Flat Fours are ideal for Fishes, planing hulls and asymetricals driven by powerful surfers. All Glass, *VERY LIMITED AVAILABILITY. 20 SETS WERE MADE AND THAT'S THAT.