Typically performance harnesses come in either 50mm or 75mm wide webbing. The 50mm webbing is a good option for fast road applications as it provides good strength without being too intrusive, but for track and race cars the 75mm webbing is a better option. The wider the webbing the larger the surface area and therefore the greater the spread of any load exerted upon it. FIA homologated harnesses must feature 75mm wide shoulder straps for this very reason.
Race harnesses typically come in two widths; 50mm or 75mm