Days on the dock are made better with the Rambler 30 oz. Tumbler. Itll 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 Design. It also comes standard with the YETI MagSlider Lid, the only slider lid that uses magnets to keep your water, beer, or favorite drink on lock.