W. is for WHOLE, but you can tell anyone what it means. No doubt that you'll love this cap! Lower profile, unstructured six panel, adjustable fastener with metal clasp, tonal under-peak lining, mid weight, flat peak, 50% wool 50% polyester. This high quality cap is made out of a wool blend. Dry clean only. Product image is One Size Fits All. We deliver worldwide with FREE DOMESTIC SHIPPING in the USA.