Smartwool Size Chart Smartwool's best selling and warmest base layer just got a little more refined with an improved fit, chafe-free seam construction and panels that offer more comfort with a pack. Its heavier, soft, 100% Merino wool fabric offers breathable warmth, moves sweat away from the body, and provides next-to-skin comfort in colder conditions Features: - Slim Fit - 100% Merino wool fabric made with an interlock knit for enhanced comfort, breathability, thermoregulation, and odor resistance - Crew neck with set in sleeves - Back body seam wraps to front for body-enhancing fit - Shoulder panels eliminate top shoulder seams - Flatlock seam construction designed to minimize chafing - Knit in Vietnam: 100% Merino Wool - Garment Weight: 200 g = 7.05 oz - Only available to ship within the USA - Last Chance: Discontinued Style