First Lite - Llano 170g Merino Short Sleeve - Material: 17.5 micron ultrafine pure 100% Merino Wool  lightweight jersey knit fabric, naturally antibacterial, meaning there is no treatment necessary to retain its odor resistant quality even when used for several days in a row 100% Pure Merino is naturally odor resistant even after multiple days of use Flat lock seams for next-to-skin comfort Versatile base layer: excellent base layer in cold conditions; excellent lightweight layer during hot weather or active hints Machine wash cold and hang dry; Covered by the First Lite Warranty