Armed with generations of outdoor expertise, Filson perfected this wardrobe staple. Made from a soft and sturdy Peruvian cotton, the waffle-knit construction of this thermal crewneck is designed to trap warm air. The Rib-knit cuffs help it keep its place amongst layers while durable materials and its bar tack reinforced side-seams slit help it stand up to wear and tear for seasons to come.