150 gsm- Our fitted Vapor Briefs provide unparalleled comfort. Simply put, nothing compares to all-natural, chemical-free, Montana-grown Merino Wool - especially when it's been woven into our proprietary Vapor Wool fabric. Why's that? Our Vapor Wool is naturally antimicrobial (odor-free), itch-free, cooling, breathable, quick-drying, moisture-wicking, and oh-so soft. Just imagine the comfort, even in the hottest of conditions. This 100% American-made item also boasts a brushed (read: soft) waistline and low-rise fit. What more can you ask of a pair of underwear?