Soft, stretchy & compressible, Capilene 4 fabric's smooth jersey face glides beneath layers; its internal grid structure retains warmth, wicks perspiration & breathes. With a deep zipper, forward-set seams, a slight drop tail, plus a discreet zippered chest pocket that's easily accessed beneath layers. Details Patagonia's warmest synthetic baselayer, Capilene 4's stretchy fabric offers great breathability & compressibility Interior grid wicks moisture, trims bulk & confers warmth Smooth jersey face slides easily beneath layers Zip-neck for easy climate control is backed by draft flap & zipper garage Raglan sleeve seams won't chafe beneath straps Vertical zippered chest pocket holds essentials, is easily accessed Drop tail keeps heat in/elements out 5.3-oz Polartec® Power Dry® polyester. Solids: 92% polyester (54% recycled)/8% spandex. Heathers: 93% polyester (47% recycled)/7% spandex. All with Gladiodor® natural odor control. 238g (8.4oz)