Wheat Straw Polypropylene | Double Wall Construction For Insulation Of Hot Or Cold Liquids | Screw On, Spill-Resistant Lid With Matching 9" Buildable Straw | Composed Of Reclaimed Stalks From Wheat | Harvested Wheat Is Renewable And Sustainable | No Indication Of Extractable Gluten In Testing | Meets FDA Requirements | BPA Free | Hand Wash Recommended