This set consists of four squares and four screws suitable for screws on double US Box type case to install a hydrofoil a board. These elements are made of stainless steel for better resistance to water, sand and salt. The screwdriving system requires a 4mm wool wrench but no screwdriver for ease of use. These 6mm squares and screws are standard to suit any US Box type case and any type of hydrofoil in classic platinum mounting.