Flying Diamonds FDX1 Futures Tri Quad Surfboard Fins - Large/GreyThis is a five fin set that can be run as a quad (pictured) or thruster. Two separate fin setups in a single package. The FDX 1 is a balanced template with all around performance. With a neutral template that is not overly upright or raked, its specifically designed to act as a single fin set that can serve as the performance baseline for any shortboard or midlength in your quiver. Built utilizing AirFlex technology with an air core of polyurethane