Downhill certified ASTM polymer shell in three sizes Superior ventilation 360° Turbine Technology Reduced peak brain acceleration by up to 30% at impact speeds associated with concussion Reduces peak brain rotational acceleration by up to 40%breakaway visor function for additional rotational impact force reduction Impact foam for superior energy absorption Moisture wicking, breathable and washable inner liner Optimal neck brace compatibility Certified and tested: AS/NZS 2063:2008, ASTM F1952–10, EN1078, CPSC 1203 Weight: From 960 ± 50g (2.12 lbs) Plastic Free Recyclable Packaging Sizing: S (55-56cm – 21 ?” - 22''), M (57-58cm – 22 ½” - 22 ¾”), L (59-60cm – 23¾” - 23?''), XL (61-62cm – 24” – 24 ½”) 
