ColdPruf Youth Enthusiast Single Layer Long Sleeve Crew Neck Top 100% Polypropylene Imported Lightweight single layer engineering with an exceptionally soft feel Seamless sides for additional layering comfort Tagless labeling and flat seems provide a smooth fit and extra comfort Moisture management system wicks perspiration and dries quickly Best used as a base layer for low bulk layering in cold to very cold weather and medium to high activity levels