Triple 8 Brainsaver EPS Helmet Rubber White Features: Measurement guide - measure circumference of your head starting in the middle of your forehead. Xsmall / Small 19.7 - 21.5 in (50 - 55 cm.) Small / Medium 21.5 - 22.75 in (55 - 58 cm.) Large / Xlarge 22.75 - 24 in (58 - 61 cm.) ABS Outer Shell with EPS liner complete with Triple 8 moisture-wicking Sweatsaver inner. Includes 2 sets of fit pads to customise fit. Adjustable chin strap with strong clip buckle. Triple Eight Dual Certified EPS Helmet White