Keep your child protected and comfortable with the Bell Sports Star Child Helmet. It features a True Fit system that self-adjusts to ensure a proper, snug fit every time. There are 11 vents in place to keep head cool on the ride. The extended rear coverage provides extra protection. It is designed for children ages 5 to 8 and fit head sizes 20.1 inch to 21.2 inch (51-54cm). Complies with the U.S. CPSC Safety Standard for Bicycle Helmets for Persons Age 5 and Older.