CONSTRUCTIONLightweight In-Mold Technology. High Density EPS &40; Expanded Polystyrene&41; Two Layer PC &40; Polycarbonate&41; Shell FEATURESAdvanced Rear Retention Adjustable Fit System Heat Sealed Removable & Washable Interior Pads SIZESS/M &40;54-58cm&41;L/XL &40;58-62cm&41;STANDARDSEN 1078