Using this Bell Sidetrack 2 MIPS child/youth bike helmet is easy. First, make sure you choose the right size according to the measurements: Universal Child (UC) for 47 - 54cm and Universal Youth (UY) for 50 - 57cm. Then, put the helmet on your child's head and use the Ergo Fit dial system with one hand to adjust it until it fits snugly. The removable visor can be attached or removed based on your child's preference and the weather. When your child is riding, the 14 vents will keep their head cool, and the sweat guide pad will keep moisture away from their eyes and eyewear. As for maintenance, you can gently clean the interior padding with mild soap and water. Let it air - dry completely before using the helmet again. Always check the helmet for any signs of damage before each ride. If there's any crack or significant wear, it's time to replace the helmet to ensure your child's safety.