* High density ABS outer shell. * Matte/Rubber shell coating * Dual-density closed cell EVA foam liner does not absorb water. * Pro-Dri plus lining wicks away moisture and provides a comfort fit. * Meets CE EN 1385 Water sports safety standards. Size Head size YS 19 in - 20 in XS/YL 20 in - 20.3/4 in S 20.3/4 in - 21.1/4 in M 21.1/4 in - 22 in L 22 in - 23 in XL 23 in – 24 in To ensure a perfect fit, measure the circumference of your head starting in the middle of your forehead and match it with the sizes below.