Bern G2 Helmet (Matte Black, X-Large) 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 59-60.5cm or 23 1/4-23 7/8 inches All-season helmet converts to summer/bike/skate conditions