Bern Brentwood Helmet Certified ASTM F2040, CPSC and EN1078 Berns exclusive Zipmold foam is a liquid foam injection process that provides a better weight to strength ratio so Bern can provide customers with a lighter, lower profile helmet. Doesn't look like a spaceship landed on your head Fits Head circumference 57-59 cm / 22 1/2-23 1/4 inches