Can be worn alone or under layers to stay dry and comfortable during high-exertion activities in cool-to-cold weather Capilene® Midweight fabric has a smooth face for easy layering, forgiving stretch and an internal diamond-grid pattern that rests lightly on the skin to trap warmth Hollow-core yarn construction increases wicking performance and speeds dry times HeiQ® Fresh antimicrobial treatment inhibits the growth of odor-causing bacteria on the fabric Raglan shoulder seams and full underarm gussets allow freedom of movement and minimize chafing; offset side seams lie smoothly under pack straps Long center-front zipper vents body heat and is backed by kissing welts for low-bulk comfort Elastic thumbholes add coziness and make layering a breeze Droptail hem; locker loop for hang-drying Fair trade certification promotes safe working conditions and sustainable livelihoods