TheK4 Stubby Rear Fin (Single)is thelower aspect line of fins for riding. Great for heavier riders applying greater power in high wind and wanting more drive in low wind. Also suitable for lighter riders in onshore conditions (upsize) or for those wanting more release to learn takas and other wave/freestyle moves (downsize). More grunt than a similar length Flex or Leon. A nice all rounder that works in all conditions and with all set ups.Flex: Dynamic FlexSizes: 14cm – 20cmUS, Slot Box and Power Box Heads