This tool less stainless steel screw and plate for all standard center fins can be tightened easily with your fingers. No more tools get you out on the water faster! NO TOOL REQUIRED, RUST PROOF: 316 Stainless Steel Will Not Rust In Fresh or Salt water. COMPATIBLE WITH 99% OF BOARDS. Fits All Standard Surfboard Fin Boxes For Longboard, SUP, Single Fin, Paddleboard. SUPER VALUE 3 Pack Means You'll Have An Excuse To Buy More Boards.