The Triple Eight Dual Certified Bike and Skateboard Helmet is the perfect blend of classic Triple Eight style, with unparalleled fit and protection. Dual-certified for both bike and skate, its ABS shell with impact-absorbing EPS foam liner is engineered for a close fit and low profile. The innovative Conehead liner construction offers additional protection with collapsing cones that act like a crumple zone to absorb the energy from a crash and spread the force sideways within the helmet liner. Ideal for biking, skateboarding, scooters, BMX, roller derby, and commuting, the helmet complies with U.S. CPSC Bike and ASTM F-1492 Skate safety standards. The Triple 8 Dual Certified Bike and Skateboard Helmet includes two different sets of removable Sweatsaver Fit Pads to customize fit, and has an adjustable chin strap with side release buckle. Available in three sizes: XS/S fits 19.7 â€“ 21.5 in (50 â€“ 55 cm), S/M fits 21.5 â€“ 22.75 in (55 â€“ 58 cm), L/XL 22.75 â€“ 24 in (58 â€“ 61 cm). To determine size, measure with a soft measuring tape or string. Helmet liners should be used to further customize the fit. Manufacturerâ€™s 180-day limited warranty.