Wheat Straw Polypropylene | Composed of Reclaimed Stalks From Wheat | Less Plastic Used In The Material | Harvested Wheat Is Renewable And Sustainable | No Indication Of Extractable Gluten In Testing | 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 | Meets FDA Requirements | BPA Free | Hand Wash Recommended