SmartWool's best selling, and warmest, baselayer, just got a little more refined with the SmartWool Men's NTS Mid 250 Pattern Crew Top, featuring a subtle pattern and improved fit. A chafe-free seam construction and panels offer more comfort with a pack. Benefits:Mid 250: SmartWool's warmest baselayer. Works as a single layer in cool weather or as a baselayer in cold weatherNTS: Next To Skin Features: Form Fit Interlock knit Crew neck with set-in sleeves Shoulder panels eliminate top shoulder seams Flatlock seam construction designed to eliminate chafing Care: Machine Wash Warm Gentle Cycle. Do Not Bleach. Tumble Dry Low. Iron Low or Dry Clean Knit in Vietnam: 100% Merino Wool