Ho Stevie! Fiberglass Reinforced Polymer Surfboard Fins - Thruster (3 Fins) FCS or Futures Sizes, Choose Color Fits any surfboard that uses FCS or Futures fins - whether it's a shortboard, funboard, or longboard. Medium template is perfectly balanced for most surfers. Hit the accelerator at your favorite point break, boost some airs, or lay into some wedges at the nearest beachbreak. FRP (Fiberglass Reinforced Polymer) design combines fiberglass with polymer to create a durable fin with better flex than standard nylon plastic fins. A more affordable option than our fiberglass honeycomb fins, without much loss in performance. 1 Year Warranty - Push it to the limit! If your fins break, we'll replace them for free.