Corsa Adult Bike Helmet L Size 23 Vents True Fit - HB-81 adjustment system with 6CM adjusting range and Ergo Design In-mold construction fuses a tough polycarbonate outer shell with the helmet's impact-absorbing foam liner 23 integrated flow vents to keep rider cool Visor offers increased shade while riding Wind Tunnel ventilation system combines active vents with internal exhaust channels that thrust cool, fresh air over your head