Stainless Steel Outer and Inner. Double Wall Construction For Insulation Of Hot Or Cold Liquids. Vacuum Insulated. Screw On, Spill-Resistant Lid. Cork-Look Rubberized Base Protects Surfaces From Heat And Scratches. Keeps Drinks Cold Up To 24 Hours and Hot Up to 12 Hours. Meets FDA Requirements. BPA Free. Hand Wash Recommended.