Triple Eight is proud to introduce its all new Dual Certified (CPSC bike and ASTM skate) Brainsaver helmet w/ EPS Liner. The new Brainsaver boast a streamlined look on the classic Brainsaver shape. But the changes don’t stop there. Construction of the EPS liner was engineered so that it complies with U.S. CPSC Safety Standard for Bike for ages 5+ AND ASTM F-1492-08 Safety Standards for skateboarding and trick roller skating. Lastly, the shape of the inside of the helmet was designed so it fits a variety of heads with a comfortable fit. To ensure a perfect fit, measure the circumference of your head starting in the middle of your forehead and match it with the sizes below. Size Chart XS/S 18.9-21.3in (48-54cm) S/M 21.7-22.8in (55cm-58cm) L/XL 23.2-24in (59-61cm)