GRAPHITE! Now with the addition of the MagSlider™ Lid, the YETI Rambler® Tumbler is better than ever! Featuring 18/8 reinforced stainless steel, DuraCoat™ Color Technology, and a magnetic slider, the 20 oz. Rambler® Tumbler offers increased ruggedness, durability, and easy use. The MagSlider™ Lid slides smoothly back and forth, and protects from splashes whether driving on bumpy back roads or hitting some waves on the water.