HB-506 Handlaminated Fiberglass Outer Shell ; EPS Inner Shell ; 10 Vents Large for Cooling Comfort ; Lightweight ; Extra Set of Fit Pads ; High Strength Polyester Straps and D-Ring Buckles ; Snell Certified ; CE and CPSC Standards ; Size: S/M,L/XL ; CM :56~60cm;60~64cm ;INCHES:22~23.5;23.5~25 ; Color :Black Blue Red White Yellow ; Vent :10