These Signature Tumblers are designed with quality in mind. Each tumbler uses double-walled technology to help reduce condensation, and allow for drinks to maintain temperature for extended amounts of time. All items are safe anywhere in the kitchen. Run them through the dishwasher, and reheat beverages in the microwave without worry. Proudly made in the USA, each tumbler is virtually indestructable and even comes with a lifeltime guaruntee!