FCS VS Knubster FCS VS KnubsterHome / Surf Hardware / Fins / FCS VS Knubster The FCS VS KNUBSTER is a centre fin that can be added to any quad set-up. The fin will increase drive and provide directional control through turns, without sacrificing speed, flow, or the freedom of movement typically associated with a quad. $16.00 Size Choose an optionOne SizeClear Quantity Add to cart SKU: N/A Categories: Surf Hardware, Fins