65% Cotton, 35% Polyester Imported Pull On closure Machine Wash Reliable Heat Retention: Made of waffle-knit fabric, our thermal shirts for men trap and retain body heat within the waffle pockets; A ribbed collar and cuffs help keep the cold out Soft Cotton-Poly Construction: Our men’s thermal long sleeve shirt is constructed of a comfortable cotton-rich blend enhanced with polyester for added durability Comfort-Driven Design: Our thermal shirt features a tagless label; Our machine-washable men’s waffle-knit long-sleeve shirt won't shrink excessively after washing Combats Cold: Our long-sleeve thermals for men help you weather cold to very cold conditions during medium-exertion activities like hiking, camping, and even lounging Versatile Sizing: Our men’s long underwear top is available in Tall sizes up to 4X