Patagonia Women's Merino 2 Lightweight Zip-Neck 80% Merino/20% Capilene fiber blend Machine wash cold Fine merino wool responsibly sourced from the grasslands of Patagonia and blended with Capilene polyester for improved wicking, durability and dry time 18.9 micron-gauge yarn; jersey-knit construction Long center-front zipper vents body heat and is backed by kissing welts for low-bulk comfort next to skin Shoulder seams are offset to minimize chafing under layers and pack Elastic thumb loops on inner cuffs; side seams offset to minimize irritation