Description Our best selling, and warmest, baselayer, just got a little more refined with an improved fit, chafe-free seam construction and panels that offer more comfort with a pack. Benefits Mid 250 Our warmest baselayer. Works as a single layer in cool weather or as a baselayer in cold weather Features Slim Fit Interlock knit Crew neck with set-in sleeves Shoulder panels eliminate top shoulder seams Flatlock seam construction designed to eliminate chafing Knit in Vietnam: 100% Merino Wool Style:A SW0NP600 Care Machine Wash Warm Gentle Cycle. Do Not Bleach. Tumble Dry Low. Iron Low. Dry Clean.