PRYDE Medium Quad Fiberglass Honeycomb 4-fin set - Futures or FCSII4 FIN SET Medium fins works great for all surfers and compatible with Futures or FCSII Tab surfboards. Ride these fins either as a twin or quad setup. These are inspired by FCS G 5 and GX fins so they fit any board that uses Futures or FCSII style fins. SPEED GENERATING 10 10 flex rating for surfing with maximum drive and controlled release PERFECT BLEND OF FLEX & STIFF These fins perform well in all surfboards, wave types, and surf conditions.