Stainless Steel Outer And Inner. Double Wall Construction For Insulation Of Hot Or Cold Liquids. Screw On, Spill-Resistant Flip-Top Lid. Measurement Scale In Ounces And Milliliters Makes Tracking Liquid Intake Easy. Removable Strainer with Blades and Strain Allows Chopping and Mixing at the Same Time. Leak-Proof. Wide Opening Makes It Easy To Add Ice, Fruit or Mixes. Meets FDA Requirements. BPA Free. Hand Wash Recommended.