Using this helmet is easy. First, adjust the fit system to make sure it fits your child's head which measures between 50 - 54 cm. Then, fasten the adjustable straps securely under the chin. When your child is riding, this helmet will keep them well - protected. Remember, always check the helmet for any signs of damage before each use. If there are cracks or other issues, replace it right away. To maintain the helmet, clean it with a mild soap and water. Don't use harsh chemicals as they might damage the shell or the interior foam. Keep it in a cool, dry place when not in use.