Patented. Copper-lined, vacuum-insulated deep draw liner maintains optimal drinking temperatures and provides 10X heat retention. Lead-free vacuum seal. Stainless Steel dual-walled construction. Durable powder coated finish. Keeps ice for over 48 hours. Sweat-free design. Features unique, spill-proof AS plastic flip top design with Tritan snap locking closure lid. 1-year limited warranty.