saruSURF US box 8 inch center fin Skeg hard plastic 8" for longboard SUP airSUP AIR7 with FREE &#39;No-Tool&#39; Fin Screw by, use as replacement or spare (Black) FOR LONGBOARD , SUP AND INFLATABLE SUP ( inflatable sup boards with air7 fin box or US box - contact us to confirm if not sure) suitable for use with most longboard / (stand up paddle) SUP / airSUP. most long board and stand up paddleboards use the universal fin system, which can take this replacement fin. STAINLESS STEEL FIN SCREW saruSURF brand US box center fin, fin screw included, no need to screw drivers, adjust your in position (forward, backward, take it off) anytime even out on the water! LOW COST REPLACEMENT for the board you let the kids use, don't want to destroy your prize fin on a shallow reef? lend your board to friends with piece of mind! TOUGH PLASTIC fin with brass pin and stainless no tools fin screw CLASSIC DOLPHIN FIN design for longboards and SUP