Fits Ages: 3-5 Head Measuring: 48-52cm / 18.9-20.5 Inches Disney Pixar’s Cars Kids’ Bike Helmet - Red/Black Pinch-Guard True Fit, 1-Step Adjustment 4-Vents CPSC Bike Compliance’s Size: Small Use: Cycling Hat Size: 6-3/4 Material: PVC (polyvinyl,chloride) EPS (expanded polystyrene)