The first day of an early-season backpacking trip on the Grand Canyon's South Rim starts in the cold snow and ends in the heat of the Inner Gorge. Regardless of the conditions, you'll stay dry and cool in this versatile crew. Capilene Lightweight is our lightest-weight, fastest-drying and best-wicking baselayer. The fabric's subtle grid pattern sits lightly and comfortably on the skin; the smooth outer face glides easily in any layering system. Highly breathable for high-exertion and warm conditions, the fabric is bluesign approved, 100% recycled polyester with 35-UPF sun protection and is treated with Polygiene permanent odor control. Features include a self-fabric collar with internal neck tape for chafe-free comfort, full underarm gussets for unhindered shoulder mobility, elastic thumb loops for secure hand coverage, flatlock seams to minimize chafing, offset shoulder and side seams to lie smoothly beneath pack straps, and a drop tail for additional coverage.