Wool and polyester play perfectly together in the X Wool Short Sleeve T-Shirt for Men. The comfortable and regulated warmth of wool is combined with lightness and durability of poly to create a superior piece that stands up to the rigors of cross country skiing, ski touring and running. An excellent first layer choice for any mountain activity. Polyester blend adds durability and shape retention compared to pure wool. This garment feels great against the skin, and only gets softer the more you wash it. Material: Merino Wool, Polyester.