The Mainstays Self-Warming Mug is a modern and stylish stainless steel coffee mug that can be electrically charged to maintain a comfortable temperature. With a solid black color and a round shape, this 12 oz mug is perfect for all occasions. It features a lid for insulation and comes in a convenient two-piece set. The self-warming feature makes it ideal for keeping your hot beverages at the perfect temperature, making it a must-have for those who enjoy a cup of coffee or tea on the go.