Cupholder Friendly: Tapered shape with handle makes it the ideal cup -- Take Us With You wherever you go. Spill-Proof Lid: Comes with a silicone straw lid to prevent spills. Lid also compatible with Simple Modern Classic tumblers. Double Wall Insulation: Keeps beverages hot or cold for hours. Durable: Made of premium 18/8 stainless steel. Limited Lifetime WarrantyPat/Pat Pend.