ColdPruf gives you a great blend of warmth and performance for those extremely cold days when you’re active. This thermal blends 2-layer warmth with moisture wicking fibers. Model: 75B Color: Grey Inside layer: 100% CPT performance polyester with SILVADUR Intelligent Freshness Outside layer: 70% polyester, 30% merino wool CPT (ColdPruf Technical Fiber®) technology helps maintain warmth while allowing moisture to pass through and stay off of the body. Merino Wool fabrication – Nature’s best material when it comes to natural fibers that are moisture wicking, lightweight and warm Two-layer engineering Traps air between layers providing a natural barrier of warmth Tagless neck label for comfort Flat seams for comfort while moving Extended tail to help stay tucked in Rib knit cuffs True-sizing for accurate fit – Bottoms : Small (28-30 inch waist), Medium (32-34), Large (36-38), XL (40-42), XXL (44-46) ThermaChoice® System – Made for Very Cold to Extreme Cold temperatures and Medium to High activity levels. These thermals are perfect for outdoor activity including work, walking, or skiing.