Acrylic Outer And Inner. Double Wall Construction For Insulation Of Hot Or Cold Liquids. Decoration Is Inserted Between The Clear Double Walls Of The Tumbler Then Ultrasonically Sealed To Provide Double Wall Insulation. Screw On, Spill-Resistant Lid With Matching 9" Straw. Stain Resistant. Lids And Straws Packed Separately And Unassembled. Meets FDA Requirements. BPA Free. Hand Wash Recommended.