Fit & Design: Eyewear Friendly: Space for your shades, leaving room for sunglass arms inside the helmet LED light compatible: Increase visibility by attaching the Universal Lazer LED to the mount at the back of the helmet Easy adjustability Winter Kit compatible: For those brisk winter rides, add the soft fleece Winter Kit for a cold weather conversion that keeps you powering through all year round (Kit not included with helmet) Technology: Lazer KinetiCore saves up to 12.82% plastic in the construction process and is the world's first responsibly designed and fully integrated impact protection technology Quick magnetic buckle Additional Details: Head Circumference in CM: 50 - 56 cm 5-star protection rating: This helmet scores an esteemed 5-star protection rating from Virginia Tech. 5-star indicates the "Best Available" rating possible CPSC 1203 COMPLIES WITH U.S. CPSC SAFETY STANDARD FOR BICYCLE HELMETS FOR PERSONS AGE 5 AND OLDER