COMPLIANCE-Complies with U.S. Consumer Product Safety Commission Safety Standard for Bicycle Helmets for Persons Age 3 and Older.Built-in sturdy impact-resistant ABS outer shell ,high density EPS inner shell provides shock-absorbing Rush tier strap system, heavy-duty nylon strap with triangle regulators,length-adjustable chin straps,hold tension well,side release buckles dual adjustable ,no sewing clips snaps heavy duty plastic,quick connect/disconnect 11 vents for increased airflow,includes 2 sets of removable,washable,velvet liners with different thickness (5 mm and 8 mm) to customize fit.Various colors and sizes for users of different ages, genders, head circumferences Classic and simple solid matte finish,adjustable fit dial on the back,turn right to tighten,left to loosen,and equiped with a drawstring bag Multi-Sports:Provide Professional Protection for Skateboarding ,Roller skating ,Inline skating ,Scooter ,Biking ,Longboard ,Rollerblading ,Hoverboard ,Street dance,Balance bike,Cycling, etc