Making it happen again & again is the Sequel. Combining the timeless lines of a Smith classic with our most advanced, ultra-light hybrid shell construction technology, the Sequel makes the old new again. Helmet Features Hybrid shell construction Airevac 2 ventilation Adjustable smith x boa™ fit system Low-profile regulator adjustable climate control 18 vents Nanosilver performance lining Snapfit sl ear pads Removable ultra-light goggle lock Skullcandy® audio compatible (available separately) Helmet sizing: (smith x boa™ fit system) + small 51-55 cm + medium 55-59 cm + large 59-63 cm + x-large 63-67 cm Certification: astm f 2040, ce en 1077:2007 class b Weight: 18.5 oz /520 grams