The QD2 4" Flat is a medium sized quad rear in Honeycomb construction. Looking to turn your favorite Thruster set into a Quad? This pair of Quad Rears can be combined with any Futures front fins to suit your riding preference, board design and waves. With a flat foil, these rears cater to quick direction changes and maneuverability. They will favor boards that have the rear boxes set toward the rail, away from the stringer.