IRH IR4G Gloss Vent Helmet International Riding Helmets (IRH) IR4G Helmet With Gloss Vent Current fashion meets advanced functionality in the IR4G helmet. Whether you're in the show ring or schooling, the IR4G's style will keep you looking cool. The comfortable chinstrap features a quick-release, easy-adjust Velcro closure and the moisture-wicking, removable liner is machine washable. Extra liners are included to provide a custom fit. See Sizing information below for more details. ASTM F1163-15/SEI Certified & CE certified to European EN 1384 Standards* *Click on Important Helmet Warning to the right Features: Quick-release chinstrap with easy-adjust Velcro closure Rear and side ventilation Snap-in liners for custom fit Machine-washable, moisture-wicking, removable liner that is Gloss Vent Item Specifications: Sizes: Small: 6 5/8 - 6 3/4 *For 6 1/2 use 5mm insert *For 6 5/8 use 3mm insert Medium: 6 7/8 - 7 *For 6 3/4 use 3mm insert *For 6 7/8 use 2mm insert Large: 7 1/8 - 7 1/4 *For 7 use 5mm insert *For 7 1/8 use 3mm insert X-Large: 7 3/8 *For 7 1/4 use 3mm insert *For 7 3/8 use 2mm insert