<P> <b>Description:</b><br/> Tighten with a cross screwdriver Against Rubber O-Ring and youre secure. <br/> A rubber O-ring to eliminate loosening while surfing<br/> Fits All Standard Surfboard Fin Boxes For Longboard, SUP, Inflatable SUP, Single Fin. Plate is 0.55"x0.55"x 0.15" (14mm x 14mm x 3.8mm). Screw is 0.157" X 3/4"(4mm x 19mm) Long. <br/> Made of Marine grade 316 stainless steel, Excellent seawater corrosion resistance and durable<br/> Package included 3 packs of 316 Stainless Steel Fin Screw and Plate, without installation screwdriver<br/> </P> <P> <b>Package Included:</b><br/> 3 Pack Fin Screw and Plate<br/> without installation screwdriver<br/> </P>