Ceramic mug with a bamboo mug warmer coaster powered by USB. Made of renewable eco-friendly bamboo. Keeps your hot beverages warm at up to 131 degrees Fahrenheit (55 degrees Celsius). Built-in MCH ceramic heating element at the bottom of the mug for faster heating. Heated Mug is equipped with a waterproof bamboo base, which can effectively protect the circuit. Hand wash ceramic mug and spot clean bamboo lid and base. Includes: 3.3 ft USB to USB Type-C cable. FCC certified. Item cannot be put in the microwave or freezer. Item is not a hot plate & warmer, it can only be used with provided mug. Size: 4-5/8" x 3-1/2" x 3-7/8".