Rambler(TM) 30oz. Tumbler.IT'LL keep your dinnertime drink cool well past sundown or your coffee piping hot throughout the morning. The Rambler 30 oz. Tumbler is made of 18/8 kitchen-grade stainless steel, has double-wall vacuum insulation, and No Sweat(TM) Design. It also comes standard with the YETI MagSlider(TM) Lid, the only slider lid that uses magnets to keep your favorite drink on lock.