This shirt combines the durability and protection of a combat jacket with the warmth of a thermal shirt. Based off the current military design to be a more comfortable uniform top under body armor and vests with the added warmth of a grid fleece body. The body of the shirt is made from 6.6oz. TRU-SPEC Performance Plus 93% polyester/7% Spandex grid fleece for increased breathability and improved moisture wicking making this shirt perfect to wear under body armor or vests during cold weather operations.