About this itemCompact and Convenient: This black mug warming plate has a diameter of 102mm/4inch and is powered by USB (non-AC). With a maximum power of 7W, it's recommended to use a charger that supports more than 5V2A for optimal performance. The general computer USB interface is only 5W is not recommended to useAutomatic Shut Off: This warmer the cup pad features 8-hour of non operation automatic shut off protection, making it safe to use even if you forget to turn it off. However, it's recommended not to leave the plate on without a cup on top for long time to prevent overheating and damage3 Temperature Settings: The USB coffee warmer is designed with three touch adjustments, just touch to easily select the right temperature, (Actual temperature.
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