Beyond its fun style and high performance, kids approve of the benefits of the K2Dialed™ Fit System, intelligently designed to adjust season after season as your kids’ noggins continue to grow, or in future seasons use for younger sibling hand-me-downs. Lining This full-coverage, washable liner snugly cradles your head, creating the unmatched fit of a K2 helmet. The liner features a crown mesh that wicks moisture and breathes to prevent overheating. The Full-Wrap Liner System is seamlessly integrated with the standard 360 K2dialed™ Fit Systems. There are no gaps, which means a better fit and improved comfort. Ventilation Channels on the inside surface of the EPS direct air-flow between your head and the helmet, removing moisture and excess heat, keeping you dry and comfortable all day long. Available on all K2 helmets. Fit System An ergonomically inspired three-point adjustable interface maximizes fit and customization. Sizing your helmet with the twist of a dial gives you the ultimate convenience of on-the-fly adjustability. FeaturesSizes: XS (48-51cm), S (51-55cm)Weight: 480 gPassive-Channel VentilationK2dialed™ Fit SystemWashable Full-Wrap Liner SystemSide Goggle Retention StrapsSummer Pad KitCertification: ASTM F2040, EN1077: 2007 Class B, CPSC 16 CFR 1203, EN1078: 2012+A1:2012