At a glance, this mug might look like your everyday drinking vessel, but look again. It&';s 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 stack perfectly on top of another one just like it. So whether you&';re storing it in the cabinets or packing it up for an adventure - it one-ups the average mug. Like the entire RamblerA(R) Family, this stackable mug and included MagSlider(TM) Lid are dishwasher safe making them easy to clean, but please note - the smooth-sliding magnet component is not leakproof and will not prevent spills. Important: Do not place mug over external heat source or open flame. Vacuum seal or other damage may occur.