Slim, Deep Fit: SLIMTECH CORE with EPS Matrix Foam is 22% thinner than a standard helmet, delivering the slimmest, deepest fit.
 
No Wiggle Fit: FLEXLOCK FIT system and 17-piece padding kit ensure a fully adjustable, secure fit to hug your head no matter how hard or big you spin

Trusted & Safe: Triple-certified to meet U.S. CPSC Safety Standard for Bicycle Helmets for Persons Age 5 and Older, ASTM F1447 for Recreational Bicycling or Roller Skating, and ASTM F1492 for Skateboarding and Trick Roller Skating. 

SIZING: XS/S: 51-54cm | S/M: 53-57cm | L/XL: 57-60cm | XL/XXL: 60-63cm | PRO TIP: We strongly recommend sizing up if your measurements fall at the upper end of a size range. Example: If you measure 54 cm, choose size S/M. Based on years of customer feedback, the larger size typically offers a better, more comfortable fit.