The QD2 4.0 Honeycomb is a medium size quad rear with a Ride Number of 5.3. 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 symmetrical foil, these rears cater to fluid rail to rail surfing and speed. They will favor boards that have the rear boxes set off the rail, closer to the stringer.