High-impact ABS external shell with high density polystyrene internal lining offers proven protection. Short-cut styling allows wide-angle vision and clear hearing. Cushioned chin strap provides added comfort. Compatible with all Maplus goggles. Adhesive labels. 'Sanitized' anallergic/breathable velvet lining. Nylon quick release retention system. Elastic band rubber fastener. Available in Silver, Black and White. Sizes: XS (54cm or 21 1/4" or 6 3/4 precise hat size) , S (56cm or 22" or 7 precise hat size) , M (58cm or 22 3/4" or 7 1/4 precise hat size), L (60cm or 23.5" or 7 1/5 precise hat size) and XL (61cm or 23 7/8" or 7 5/8 precise hat size). To determine helmet size, position a tape measure around the largest circumference of your head just above the ears and about 1/2" above the eyebrows, then note the correct size at point of overlap.