Pro-Tec Classic Certified Skate Helmet X-Small size professional quality classic helmet for action sports; fits head 20.5-21.3 inches (52-54cm) Outer ABS shell and inner EPS foam liner protect against hard, fast falls and high-impact slams Plush moisture wicking liner and fabric prevents dripping sweat, allowing wearer to stay drier and focus 11 large vents improve flow-through air channeling to keep the wearer cool during intense action sports Loved by skaters through 40 years of pioneering design and Certified by independent scientific tests and safety standards