Using the Hornit Lid Kids Helmet is easy. First, adjust the ring adjuster at the back of the helmet to fit your child's head size. Then, use the three - way adjustable chin strap and buckle it securely under the chin. Make sure the helmet sits snugly on the head. When your child is riding, the 11 air vents will keep them cool. The rear safety light has multiple flash modes, and you can switch it according to the situation. As your child grows, you can remove and adjust the soft foam inside for a better fit. For maintenance, wipe the helmet with a damp cloth regularly. Avoid using harsh chemicals as they may damage the helmet. Store it in a cool, dry place when not in use.