Using EPS foam for certified protection and 11 air vents to keep your head cool...
CPSC 1203 Certified (USA - Skate/Bike) - Meets the skate and bicycle helmet certification standards of the Federal Consumer Product Safety Commission. Designed to withstand a single high impact or multiple low impacts.
Head Circumference...
XS - 52-54cm / 20.5" - 21.3"
S - 54-56cm / 21.3" - 22.0"
M - 56-58cm / 22.0" - 22.8"
L - 58-60cm / 22.8" - 23.6"
XL - 60-62cm / 23.6" - 24.4"