Yetis Rambler®20 oz Tumbler is made from durable stainless steel with double-wall vacuum insulation to protect your hot or cold beverage. 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. Product Information: Product Code: SKU305-BLACK Capacity 591ml/ 20oz Empty Weight 358g