You love a good storm day as much as carving under blue skies. The Smith Altus ski and snowboard helmet lets you adjust the venting on the fly to match the weather conditions and your output. Of course, it brings safety innovations including zonal Koroyd and MIPS for the confidence to get after it in any snow conditions, too. It's light enough for backcountry missions and cuts a classic profile.Size: Small - 51-55cm Medium - 55-59cm Large - 59-63cm XLarge - 63-67cm