Giro Raze Cycling Helmet - Kid39;s The Giro Raze Helmet uses the same In-Mold technology used in adult models; construction bonds the shell to the helmet for a lightweight, durable design Acu-Loc fit system offers a wide range of adjustment and extra stability while simplifying the fit process 22 vents allow cool, fresh air to circulate over and around your child's head, and let hot, stale air escape Removable snap-fit visor shields eyes from sun; reflective rear decal enhances visibility Head circumference: 19.75 - 22.5 inches