AtomicFour Amid Pro Helmet Size Large ( 59-63cm) White - New with tag in box as shown Ride confidently in this low-profile, urban-inspired helmet Hybrid in-mold construction is lightweight and stable Multiple layers of protection help absorb forces when you fall Advanced ventilation system actively moves heat away 360 fit system adjusts with the gloved turn of a knob Merino 3M X-Static lining manages moisture and odors Item #ATOK189 This year, Atomic decided to take a new approach to their all mountain helmet design. The Four Amid Pro Helmet is the pinnacle of this, with sleek, street-inspired style, a comfortable fit, and protection you can ride in with confidence. Built with AMID, which stands for Atomic Multi-directional Impact Deflector, the helmet's defense systems are designed to absorb the force of angled impacts, while the Holo Core design incorporates a crumple zone that maximizes shock absorption. Tech Specs Shell Material ABS Impact Foam EPS, AMID, Holo Core Audio Compatible yes Ventilation Aircon Fit Adjustment 360 dial Certifications ASTM F 2040 / CE EN 1077:2007 Class B Claimed Weight [small] 13.4oz