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 to fasten the helmet securely under the chin and lock it with the buckle. When your child is out riding, the rear safety light can be turned on to make them more visible, and you can switch between different flash modes. As your child grows, you can remove the soft foam to adjust the fit. When it comes to maintenance, clean the helmet with a mild soap and water solution. Avoid using harsh chemicals as they may damage the helmet. Make sure to let it dry thoroughly before storing it in a cool, dry place. Also, check the helmet regularly for any signs of damage, and if you notice any cracks or wear, replace it immediately for your child's safety.