Omni-Wool Dual-Layer Merino Wool Blend Zip Top Machine wash - no bleach - tumble dry - do not iron Outer layer: 80% Polyester, 20% Merino Wool / Inner layer: 100% Polyester Soft, breathable dual-layer fabrics that stretch for optimum fit Moisture wicking to keep you dry, warm and comfortable Integrated thumb hole Flatlock stitch construction for superior strength