Cowabunga, dude! Rule the tracks and parks with this multisport helmet featuring all 4 Teenage Mutant Ninja Turtles. This helmet is constructed with a shock absorbing inner shell and stays snug with an easy to adjust chin strap. CPSC 1203 Bike and ASTM F1492 Skate compliant. For ages 5-8. Fits head sizes 19.7-21.2" (50-54cm).