61 CM X-Large - Silver. The Stilo ST5 GT Composite helmet is an iconic helmet used in a variety of race types. Crafted from a multi sandwich Fiberglass composite layup and exceeding the Snell SA2020/FIA 8859 ratings, this helmet features an array of improvements from the ST4 Helmet Line. Weighing in at 2.99lbs in the small shell size and 3.74lbs in the large shell coming in Silver this helmet not only looks good but will minimize neck and head strain. The ST5 GT helmet most notably includes side ports on either side of the helmet which allow drivers to customize their helmet with an array of accessories. These accessories include an array of electronic integrated communication systems, as well as drink & air systems.