HJC Ace Men's FG-17 Sports Bike Racing Motorcycle Helmet - MC-10 / Medium The race-ready helmet tested at Wind Tunnel Laboratory Advanced Fiberglass Composite Shell: Lightweight, superior fit and comfort using advanced CAD technology All sizes of cheek pads are interchangeable in all helmet sizes SilverCool Interior: Moisture-wicking and odor-free liners Crown and cheek pads are fully removable and washable