HB-504 Handlaminated Fiberglass Outer Shell ; EPS Inner Shell ; 18 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 :S/M;L/XL ;CM :56~60cm60~64cm ; INCHES:22~23.5;23.5~25 ; Color :Black Blue Red White Yellow ;Vent :18