Dual Certified skateboarding and bike helmet with ABS shell and impact-absorbing EPS foam liner Complies with U.S. CPSC Safety Standard for Bicycle Helmets for Persons Age 5 and Older and ASTM F-1492 Skate safety standards Ideal for biking, skateboarding, scooters, BMX, roller derby, and commuting Includes two different sets of removable, moisture-wicking Sweatsaver Fit Pads to customize fit; adjustable chin strap with side release buckle Size XS/S fits 18.9 – 21.25 in (48 – 54 cm), S/M fits 21.5 – 22.75 in (55 – 58 cm), L/XL 23.25 – 24 in (59 – 61 cm); manufacturer’s 180-day warranty