Unlike traditional camp mugs, this double-wall, vacuum-insulated body protects hands from hot or cold contents while keeping coffee, chili, or oatmeal nice and hot. And now, it stacks up and stores out of sight. Like all Rambler® Drinkware, the mug and lid are dishwasher safe. Please note: the mug's wide opening means content may cool quicker. That's why the mug comes with the MagSlider™ Lid.