It's lined with fleece, so it's warm. This is an LL-size inner shirt made of 100% polyester, providing excellent heat retention. It can be worn as underwear, and since it's black, you can also wear an outer layer directly over it for a stylish look. - Size: LL - Material: 100% Polyester Thank you for viewing. #Shimamura #Uniqlo #Wacoal #Chale #Diana