The mug is with you whether you are driving long distances in the car, in the office or on a tough outdoor adventure. The cup ensures that your liquid can keep its temperature. The mug is made with double wall insulation with copper lining for maximum insulation. The liquid can keep the heat for 6 hours and the cold for 18 hours. The design of the mug allows it to sit in your cup holder, no matter what size you choose. The mug is made from non-reactive and lightweight 18/8 stainless steel, which has higher corrosion and oxidation resistance than regular steel, this prevents odors and is easy to clean. It is also BPA-free. The lid is completely waterproof.