My son used less than 20 times before outgrowing. LS2 helmets feature a Dynamic Flow-­through Ventilation. Fully adjustable intake ports and vented EPS work with the rear spoiler and exhaust ports to create a constant, light flow of air helping to keep the rider cool and comfortable. Certified: ECE 22.05 Liner: Removable and Washable, breathable, hypoallergenic, laser-cut foam