Hocosa Short-Sleeve Underwear Shirt in Organic Wool-Silk Blend, Unisex, Natural White 70/30 blend of soothingly soft European KbT- certified organic merino wool & silk. Wool for warmth. Silk for strength & durability. Natural fibers breathe, maintaining a comfortable temperature in warmth or cold. Light-weight. Comfortable under clothing or worn alone. Wool absorbs moisture without feeling wet, keeping you dry & comfortable. Even when wet, feels warm. Natural wool with lanolin gives self-cleansing properties, minimizing need for washing. Can go weeks without washing, even with daily wear. For best results, wash by hand with lanolin-replenishing woolwash to maintain hygienic effects. See Product Description below for more info.