YETI Black Rambler 14 oz Mug with Magslider LidThe custom YETI Rambler 14 oz. Mug is one of the toughest, most over engineered camp mugs out there. Unlike traditional mugs, this double wall vacuum insulated body protects hands from hot or cold contents well insulated. The mugs wide opening means contents are easily accessible but will cool quicker. Thats why the cup comes with the MagSlider Lid, which adds a barrier of protection to prevent heat or cold from escaping.