This mug is loaded with top to bottom insulation to keep your coffee hot from the first pour to the last sip. And it's a space saver. When the lid is removed, the built in grooves on the bottom help it nest perfectly with another just like it. Plus its got an ultradurable ceramic lining for easier cleaning. Like all YETI Rambler Drinkware, the mug and lid are dishwasher safe. Like the entire Rambler Drinkware Family, this stackable mug and included MagSlider Lid are dishwasher safe making them easy to clean. Each mug is sold separately. Note, do not place mug over external heat source or open flame. Vacuum seal or other damage may occur. This magnet slider is not leakproof and will not prevent spills.