Elegant and durable brushed stainless steel exterior, Insulated screw stopper with narrow-mouth opening, Double-wall polyurethane insulation, Contoured handle is comfortable to hold for easy portability, SS material used is food-grade and non-magnetic, Plastics used are food-grade and virtually unbreakable, Keeps hot beverages hot for 6-8 hours when used as suggested, Keeps cold beverages cold for 8-10 hours when used as directed.