YIXUAN Always keep extra screw and fin plate in your paddle bag for replacement. This set of Screw Fin Plate is a universal fit for most fin box on the market and need no screwdriver to install it. Say goodbye to your screwdriver It is designed to move a fin back or forward, install fins in a perfect position. Features: 304 stainless steel construction, rust and corrosion resistant. Eliminates the hassle of using a screwdriver in surfing. Measure 14 * 14 * 3mm (0.55 * 0.55 * 0.12) for plates. Fits industry-standard fin boxes. A rubber O-ring to eliminate loosening while surfing. A perfect and must-have replacement fit for long board surfers. Specifications: Material: 304 stainless steel Model: M4 Screw size: 4 * 30.85mm / 0.16 * 1.21in Thread length: 17mm / 0.67in Plate size: 14 * 14 * 3mm / 0.55 * 0.55 * 0.12in Item weight: 9g / 0.3oz (One Pack) Package size: 12.5 * 8 * 1cm / 4.9 * 3.1 * 0.4in Package List: 3 * Screw+3 *Plate