PowerBridge molded force absorberLightweight polymer shell, available in three sizesEasy-access, secure sunglass storage Fidlock magnetic closure system360° Turbine technologyReduces peak brain acceleration by up to 30% at impact speeds associated with concussionReduces peak brain rotational acceleration by up to 40%Adjustable visor with breakaway function for reduced rotational impact forceMolded shock-absorbing foam for superior energy absorptionMaximum ventilation with 20 effective vents even when riding slowlyAnti-odour interior wicks away moisture, eliminates odours and reduces the risk of injury.moisture-wicking, odor-resistant interior, washable and breathableCertified and tested: AS/NZS 2063:2008, EN1078, CPSC 1203Weight: from 350 g (0.78 lbs)Size#S (51-55cm - 20-21 58") #M (55-59cm - 21 58- 23 14") #L (59-63cm - 23 14 - 24 34")