The ultra-durable tumblers made with kitchen grade 18/8 stainless steel and the double walls vacuum insulate your beverage, keeping it hot or cold longer. The tumblers have a flat bottom, so they can be used with or without the stems. Great for picnics, camping, outdoors and anywhere else traditional wine glasses might break. Kitchen grade 18/8 stainless steel tumbler is vacuum insulated to maintain hot or cold beverage temperatureFully sealed BPA-free lid and color-coded stemsColorful, removable stems can be used to keep track of whose drink is whose