This mid-weight hat has a removable pom pom that snaps on and off for style. The hat is made of 50% polyester, 35% merino wool and 15% nylon bi-layer. Terramar bi-layer construction creates an air pocket in-between both layers for additional insulation and thermal regulation. Terramar Merino wool is blended with nylon for an added degree of durability. Merino wool is nature's best at thermal regulation and odor control.