The Trace is the pinnacle helmet in Smith's performance road collection. The Trace features Koroyd, which fully surrounds the helmet providing exceptional protection and works with the internal air channels and open intake and exhaust ports produce maximum ventilation. Storage and ventilation of eyewear is crucial on those long rides, the Trace's AirEvac system relieves hot air that builds up on your eyewear to prevent fogging. Eyewear storage is made easy by channels on the side of the helmet that hold your eyewear in place for those grueling climbs. FEATURES : Lightweight Aerocore in-mold construction Complete ventilated protection featuring Koroyd Integrated skeletal structure VaporFit adjustable fit system 18 optimized vents XT2 anti-bacterial performance lining Ultra-light single layer webbing AirEvac ventilation Ultimate eyewear integration Light mount compatible SPECS : Weight : (Size M, MIPS) 10oz / 280 grams Certification : CPSC Sizing Small: 51 - 55cm Medium: 55 - 59cm Large: 59 - 62cm