Any custom tumbler that's coming along for the ride needs to be tough enough to keep up. The 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. While the magnet on the included MagSlider Lid adds an additional barrier of protection for keeping drinks contained and preventing heat or cold from escaping, please note - this magnet component is not leakproof and will not prevent spills. Because the YETI Rambler is customizable with your company's logo, it makes for a great corporate gift. 18/8 Stainless Steel: puncture- and rust-resistant. Double-wall vacuum insulation. Keeps drinks cold drinks cold and hot drinks hot until the last sip. Dishwasher safe. Cupholder Compatible.