The FIRST and ONLY helmet to fully integrate the best of high impact absorbing EPS Foam with thick dual density soft foam and plush Sweatsaver fabric, delivering the ultimate in comfort with dual certified protection. A portion of sales will be donated to the The Skatepark Project (formerly The Tony Hawk Foundation) to continue its mission of empowering youth through the creation of public skateparks in low-income communities. Dual Certified: Complies with U.S. CPSC Safety Standard for Bicycle Helmets for Persons Age 5 and Older and ASTM F-1492 Skate safety standards. Includes 2 sets of Sweatsaver liners to customize fit. Sweatsaver Comfort. Thinner Liners. Thicker Liners. Sizes: XS/S 20 – 21.25 in (51 – 54 cm), S/M 21 – 22.5 in (53 – 57 cm), L/XL 22.5 – 23.5 in (57 – 60 cm), XL/XXL 23.5 – 24.5 in (60 – 63 cm).