Donut Shape Coffee Mug Warmer, Constant Temp Cup Warmer

Constant Temperature Heating: This coffee warmer features a 4.25 inch (10.8cm) heating area and provides consistent temperature heating to slow down the cooling of your beverages. The surface temperature can reach up to approximately 167°F (75°C), while keeping the liquid temperature around 104°F (40°C). Please note that actual results may vary depending on the environment and the type of cup used. Simple USB Operation: Just plug the mug warmer into a USB port, press the switch, and place your cup on the heating surface. The built-in indicator light shows the working status—lighting up when heating and turning off when stopped. It is recommended to connect it to a computer, so the warmer will automatically stop when the computer is turned off. Wide Compatibility: The warming performance may vary depending on the material of the cup. Thin-walled, flat-bottomed mugs provide the best results. This mug warmer works well with stainless steel, ceramic, and glass cups. Using a lid can help retain heat more effectively. Versatile Use: Suitable for a variety of cup materials including metal, enamel, ceramic, and glass. Ideal for keeping beverages such as coffee, milk, tea, and hot chocolate warm. (Note: Cup is not included.)