YOUR DRINK OF CHOICE ON THE GO. FITS IN MOST CUPHOLDERS. The Rambler® 30 oz. is the tumbler that gets you through the day. Your morning brew will stay hot or your iced coffee will stay cold — so take your time. Kitchen-grade stainless steel with double-wall vacuum insulation work together protect your drink at all costs. Like the entire Rambler® Drinkware Family, the 30 oz. Tumbler and MagSlider™ 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, this magnet slider is not leakproof and will not prevent spills.