Stainless Steel Outer And Inner, Double Wall Construction For Insulation Of Hot Or Cold Liquids, Snap-On, Spill-Resistant Thumb-Slide Lid With Rubber Gasket, Due To Vacuum Insulation Technology, Capacity Is 18 Oz. With Lid On, Keeps Drinks Hot Or Cold Up To 6 Hours, Non-Slip Bottom, Meets F-D-A Requirements, BPA Free, Hand Wash Only