Square and screw for hydrofoil double US Box

This product is constituted of 4 squares and 4 screws adpted for a double US Box to instal a hydrofoil on the board. These compoments are made with inox to ensure a better resistance to water, sand and salt. The tightening system requires a 4mm key but no screwdriver to make an easier use. These squares and screws correspond to the norm so they can fit any double US Box and any hydrofoil with a classical top plate mount.