Coffee warmer can keep your coffee at the most suitable temperature for drinking. Safe and Convenient Design: The coffee mug warmer uses a tempered glass heating plate with a waterproof design. The heating plate diameter is 3.4 inches, which fits most size mugs. Get the Best Coffee Drinking Experience: It is highly recommended to use flat-bottomed, thin-walled glass, ceramic, stainless steel and other cups with good thermal conductivity. The Best Gift Choice: The exquisite packaging is very suitable as a gift. It is the best gift for your family and friends on Christmas, birthday and other occasions.