Design & Technology: Adult bike helmet designed for ventilation with reduced weight 12 active vents provide optimal breathability for added comfort ThinShell construction offers a durable build EZ-Fit System is an elastic system that auto adjusts for a more comfortable fit All-season design lets you fit the helmet with seasonal liners for comfort in changing weather Weight: 253 g Standards: CPSC, EN-1085 Sizes: S, M, L Style: MAC2NAM