Camco's Life Is Better At The Campsite Wine Tumbler Set is a great addition to any campsite, tailgate, or party. They are ultra-durable and made with kitchen grade 18/8 stainless steel. The double walls vacuum insulate your beverage to keep it hot or cold longer. They have a flat bottom and can be used with or without the colorful stems. The stems can be used to color code drinks or help keep track of whose drink is whose. The lid is BPA Free and has a fully sealing gasket to help maintain beverage temperature and prevent spills.