Any tumbler that comes along for the ride needs to be tough enough to keep up. The Rambler 20 oz. Tumbler, featuring Ramakko’s custom Source Your Adventure design, is made from durable stainless steel with double-wall vacuum insulation to protect your drink’s temperature at all costs. Like the entire Rambler Drinkware Family, the tumbler and MagSlider Lid are dishwasher-safe for easy cleaning. While the magnetic MagSlider Lid adds an extra barrier to help keep drinks contained and temperatures locked in, it is not leakproof and will not fully prevent spills.