Men's Furnace Quarter ZipLayering Position Midlayer Features True to size: Purchase your normal size to wear over or under other layers 20. 5 micron, superfine, merino wool 95% merino 5% spandex Expedition weight, fleeced Merino fabric for extreme cold Quarter zip neck for strategic ventilation Modified raglan sleeve moves seams out from under backpack shoulder straps Ergonomic cuff with thumb loops Flatlock seams Machine wash, line dry Materials 95% Merino wool and 5% Spandex