Endorfins KS1 Single Tab Tri-Fin SetA better build innovative carbon inlays in Endorfins add strength and flex that enable them to be built with a core comprised of 90% pure air. As a result, Endorfins not only provide optimum performance but also literally float on water. The Futures compatible base on Endorfins will work just like a fin built by Futures with a Futures base. Designed by 11 time world champ "Kelly Slater" Fin Size Details Size Front Fins Center Fins Medium Height: 4.