Multi-Use Lid: Featuring two interchangeable lid pieces, you can choose your preferred sipping method - straw or chug - and easily swap out the sipping component within the lid at any time. Functional: Ergonomic handle design allows for a comfortable grip, making it a breeze to transport while pivoting from one daily activity to another. Double Wall Insulation: Keeps beverages cold or hot for hours. Durable: Made of premium 18/8 stainless steel, and comes with a silicone boot to soften landings and enhance stability. Limited Lifetime Warranty & Pat/Pat Pending