HB-501 Handlaminated Fiberglass Outer Shell ; EPS Inner Shell ; 15 Vents Large for Cooling Comfort ; Lightweight ; Extra Set of Fit Pads ; High Strength Polyester Straps and D-Ring Buckles ; Snell B-95A Certified ; CE and CPSC Standards ; Size :XS/S ;　 　 CM :52~56cm ;INCHES:20.5~22 ; Color :Black Blue Red White Yellow ;Vent :15