Hardshell construction 8 vents Side-squeeze buckle for easy adjustment CPSC 1203 Bike and ASTM F1492 Skate compliant This great looking Avengers multi-sport helmet is both CPSC 1203 Bike and ASTM F1492 Skate compliant. Eight vents help with cooling, and a side-squeeze buckle make adjustment easy. The graphics beautifully bring Avengers to life. Fits head sizes 50-54 cm and recommended for ages 5-8.