ColdPruf Men's Platinum Dual Layer Long Sleeve Crew Neck Top Inside 100% CPT Performance Polyester/ Outside 70% Polyester, 30% Merino Wool Imported Tagless Garment with Flat Seams for Comfort Extended Tail True Sizing for Accurate Fit Thermachoice System: Very Cold to Extreme Cold Weather / Medium to High Activity Ring Spun Yarns Provides Exceptional Softness ColdPruf Technical Fiber Polyester with SILVADUR Intelligent Freshness. Odors Off. Fresh On!