The Smith Altus ski and snowboard helmet lets you adjust the venting on the fly to match the weather conditions and your output. the lightweight in-mold construction makes for a one-piece design which is lightweight and durable for the confidence to get after it in any snow conditions, too. It's light enough for backcountry missions and cuts a classic profile DESIGN & DETAILS: Lightweight in-mold construction fuses the exterior shell and EPS foam for a one-piece design that's lightweight and durable Zonal KOROYD® coverage for lightweight, energy-absorbing and ventilated impact protection Certification: ASTM F 2040, CE EN 1077:2007 CLASS B Designed for ultimate integration with Smith goggles for maximum comfort and venting AirEvac ventilation system integrates with Smith goggles for fog-free lenses VaporFit Snow dial adjustment system offers 270-degree fit adjustment with the turn of a dial Removable, Aleck® audio systems compatible ear pads Regulator climate control allows easy, one-handed vent adjustment Ionic+® antimicrobial lining offers sweat-activated odor control 10 adjustable vents Weight (Size M): 16oz / 450g