[Trustworthy Skateboard Helmet: Impact-resistant ABS shell and shock-absorbing EPS foam with a 0.7-inch thickness for durability and reliable protection. Complies with U.S. Consumer Product Safety Commission Safety Standard for Bicycle Helmets for Persons Age 5 and Older Available in 3 Sizes: Small (51-54 cm / 20.1"-21.3") suitable for toddler child boys girls medium (55-58 cm / 21.7"-22.8") suitable youth adult and large (59-61 cm / 23.2"-24") suitable for teen adults. Please measure your head as sizes may vary within the same age range Easy to Adjust and Comfortable: Two sets of different sizes full-range liners (5mm and 8mm) and an easy-adjust dial system allow for flexible adjustments to achieve the perfect fit. 12 top and side vents ensure optimal airflow keeping you cool and comfortable even on hot days "Dial-Adjust Fit System with Special Features: The dial and cage can be moved up and down providing greater adjustability for a more customized fit. This Cycling helmet is an excellent choice as a gift for Childrens Day Christmas birthdays Thanksgiving and other festivals" Application: The skate helmet is designed for toddlers kids boys girls child teens women and men. Choose from a variety of matte colors to perfectly match your bike skateboard scooter hoverboard longboard and more]