150 gsm - The Duckworth team proudly states the following with no hyperbole: our fitted Men's Vapor Brief is the World's Best underwear. Period. Nothing keeps you more comfortable (where it counts) than all-natural, chemical-free, Montana-grown Merino Wool spun and 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 and most-humid of conditions. Oh yeah, this 100% American-made item also boasts a brushed (read: soft) waistline and functional fly. What more can you ask of a pair of briefs?