Design Philosophy Using learnings from the award winning MT500 Helmet, working closely with Koroyd Endura have developed a revolutionary kids helmet which out performs the current EN safety standard by a considerable margin. The Koroyd inserts provide enhanced energy absorption while keeping weight low and ventilation high. 90 day satisfaction guarantee So confident are we in this product that, if you are not entirely satisfied with it then we offer a no-quibble refund or replacement policy within 90 days of purchase.