Any tumbler that's coming along for the flight needs to be tough enough to keep up with the aircrew life. This is a genuine YETI Rambler® 20 oz. is made from durable stainless steel with double-wall vacuum insulation to protect your hot or cold beverage at all costs. Like the entire Rambler Family, the 20 oz. Tumbler and its lid are dishwasher-safe for easy cleaning.