Keep Cold/Hot for Hours Insulated coffee mug is made of high quality 304 food grade stainless steel, BPA free, safe and non-toxic, durable and reusable. With double-layer vacuum insulation technology, it can keep your drink hot or cold for hours. Say goodbye to big bulky water bottles and easily enjoy your favorite beverage while commuting and on the go. Ideal Size Travel coffee mugs are available in 2 sizes (12oz/380ml, 17oz/510ml) and a variety of colors to choose from. The diameter of the bottom of the cup is 2.7in/ 7cm, which is compact and lightweight enough to fit in your car cup holder. This portable coffee mug is suitable for indoor and outdoor, office, party, traveling and many other occasions.