Uniqlo Heattech Extra Warm This underwear is made with a cotton inner layer, making it recommended for those with sensitive skin. It's a men's XS size. I purchased this a few years ago and have stored it at home. Please understand this before purchasing. - Brand: Uniqlo - Size: Men's XS - Material: 100% Cotton - Technology: JAPAN TECHNOLOGY - Features: Extra Warm Thank you for looking.