Product details:
Shell is constructed with durable Polycarbonate. Ultra-plush removable/washable padded liner keeps you cool and dry by wicking away sweat. Adjustable visor design. Intake and exhaust vents for ventilation and cooling. Durable multi-colored clear coated graphics. Meets DOT standards. For proper fit and size measure the circumference of your head 1 above your eyebrows and around the largest portion of the back of your head. 20 1/2 - 21 1/8 -------- X-Small 21 1/4 - 22 1/8 -------- Small 22 3/8 - 23 1/8 -------- Medium 23 1/4 - 23 3/4 -------- Large 23 7/8 - 24 3/4 -------- X-Large 24 7/8 - 25 1/8 -------- XX-Large