This lightweight vented riding helmet from Zilco features Rear helmet dial adjustment allowing micro adjustment of size to suit rider head profile. Front ventilation with mesh screen for increased airflow and cooling. Removable padded inner lining allows hat to remain fresh Sleek channel design aids airflow through vents Ultra light design weights 400g Manufactured to ASTM F1163-04A (USA), EN 1384 (UK & Europe) Colour Charcoal Grey/Silver Sizes Small 51-54cm, Medium 55-58cm, Large 59-61cm