Wigwam Gobi Liner This liner sock is light weight polypropylene, designed to move moisture away from your feet. Features: Wear under heavier socks to achieve maximum benefits This liner will act as a 2nd layer of skin to prevent blisters 1x1 stay-up true rib leg Smooth looped toe seam for added comfort 100% Polypropylene - An extremely light and superior moisture repelling fiber. Also displays a higher thermal insulating power compared to other fibers