USB Coffee Mug Warmer W/ Automatic Shut Off

This mug warmer can turn hot water into warm water, and heat cold water. Keep or warm up the liquid temperature to as high as 131F, flat-bottom will get the best warming performance. Coffee cup warmer plates have no groove, so it can fit most cups, such glass cup, stainless steel cup, ceramic cup etc. We recommend using the cup with flat bottom for better heating results. Do not use the computer USB port to power this. 6.42" L x 4.92" W x 1.89" H