The Enthusiast(TM) layer for when adventure takes precedence over temperature. The Enthusiast Crew by Coldpruf features 5.5 oz. 100% Polypropylene Thermal which offers a lightweight, thermal insulation that gives you the freedom to move. Designed to be worn in cold to very cold environments. Allows for medium to high activity. True sizing for an accurate fit. Pairs with the Enthusiast Pant. | Coldpruf Enthusiast Crew Thermal Shirt in Black | Size Small