The O2 features 24 vents and Internal ventilation channels for optimum airflow.Rollsys Retention SystemRigidity Brace System: Reinforcements for a superior helmet resistance against multi impactsInternal ventilation channels for optimum airflow and Coolmax paddingIn-Mold (2 pieces) and 24 ventsUnisize weight 310gLG-2XL weight 345gLazer has a simple crash replacement program available through participating dealers. See your dealer for details21 vents305 gramsLazer has a simple crash replacement program available through participating dealers. See your dealer for detailsItem SpecificationsColorWhite/RedWeight310gFits53-61cmGenderMen"sSizeOne SizeHelmet StyleRoad PerformanceDefined ColorRedVisor IncludedNo