The AR1 helmet is Answer Racing's best value helmet, all while meeting or exceeding D.O.T. and E.C.E. safety standards. A dual-density EPS liner helps to absorb both large and small impacts while a highly developed ventilation system consisting of multiple intake ports and exhaust ports help keep you cool in warmer weather. Features and Benefits Multiple air intakes and exhaust vents to keep air flowing Removable, washable cheek pads and liner Meets or exceeds ECE 22-05/06 and D.O.T. FMVSS 218 safety standards Injection molded polycarbonate and ABS shell Sculptured, dual-density, EPS impact absorbing liner Size Head XS 20-3/8” - 21-1/8” 52 / 54cm SM 21-1/4” - 22” 54 / 56cm MD 22-1/8” - 22-7/8” 57 / 58cm LG 23“ - 23-3/4” 59 / 60cm XL 23-7/8” - 24-5/8” 61 / 63cm 2XL 24-3/4” - 25-1/2” 63 / 64cm