The Smartwool Unisex Rib Hat may look ordinary, yet this unassuming beanie offers more than meets the eye. The Rib Hat is crafted with a unique proprietary Smartwool blend featuring Merino wool, recycled polyester and nylon. This yarn blend offers durability and breathability along with Merino wool's distinctive soft feel and odor-control properties. It also integrates a single-layer heavy rib knit construction for density, flexibility and a super-soft feel. Keep your Rib Hat in top condition by machine washing it in cold water and laying it flat to dry.