Designed for mid-length fish surfboards, the Futures fin box fits the Quad Keel Fin. The performance of the quad fin is also a good balance between the speed and turning performance of the Keel Fin. By widening the base of the fin (the width of the root) you can feel elongation (driving) during turn, and the sweep is also stronger, so it is designed to allow you to enjoy larger turns compared to standard quad-fins. Compatible with fish boards for extended turns. Besides the nanazero surfboard, it will fit surfboards that use Futures fin boxes. Please check the specifications of the fin box before purchasing. Set of 4 front and back. Set the logo on the outside.