Double-wall vacuum-insulated Stainless Steel with Copper lining The world's first universal coffee (or beverage) insulator! Designed to insulate nearly all iced / hot coffee cup sizes (from Starbucks, Dunkin Donuts, McDonalds, etc.). Keeps contents cold for 24+ hours Keeps contents hot for 6+ hours Cup holder compatible Non-slip Silicone bottom Includes 2 accessories: a to-go beverage collar and a 100% leak-proof lid for normal tumbler function - 32 oz capacity Powder-coated styles (laser engraved only), Silicone rings and lids are dishwasher safe. Glitter and graphic styles are hand wash only Patent pending 1-year limited warranty