For those that never sit down & always operate at a low buzz, youll be happy to know theyve got the Zoom helmet to protect their domes when theyre straight lining in a high-speed wedge. Helmet Features Lightweight in-mold construction Airevac 2 ventilation New adjustable dial fit system (dfs 2) Airflow climate control Super soft, furry tricot lining Removable goggle lock Helmet sizing: new dial fit system (dfs 2) + youth small 48-53 cm + youth medium 53-58 cm Certification: astm f 2040, ce en 1077:2007 class b Weight: 12 oz / 350 grams