The mt500 helmet uses 3d formed koroyd inserts for enhanced airflow and improved energy absorption in an incredibly lightweight package it is one of the most breathable and lightweight enduro helmets on the market while also providing superior impact protection over standard construction koroyd technology engineered protection tens of thousands of copolymer extruded tubes thermally welded to create an unparalleled consistent and fully engineered core ready to be cut shaped cnc ed the