ColdPruf Men's Extreme Performance Base Layer Long Sleeve Shirt - The Extreme Performance garment has been constructed with 2 layers of 96% CPT - COLDPRUF technical Fibers and 4% Spandex for superior fit, Warmth, maximum dryness and odor control. The Extreme Performance two layer garment has been specifically engineered with our COLDPRUF (R) Technology to trap air between the layers of fabric to provide a natural warmth shield. The Extreme Performance is excellent for wear in very cold to extreme cold environments with medium to high activity. 2 Layer Flat Seamed Drop Tail Rib Cuffs Four Way Stretch Tagless Wicks & Evaporates Moistures Antimicrobial