The Rambler® 30 oz. is the ideal tumbler for everyday use. Your morning joe stays hot, and your iced coffee will stay cold - so take your time. Kitchen-grade stainless steel with double-wall vacuum insulation will protect your drink at all costs. 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.