Military issue wool/cotton thermals. Some call these the "Wallace Berry Suit". These are 50% wool/50% cotton. DSA100-75-C-1391. New, old stock.
While these are new, the XL size pants all have some brown cardboard / dust stains from storage. Most of the stains are right along the folds where the garment has rubbed up against the wax protection in a carton. Performance will not be affected but they do show signs of staining.