Review on ☕ SEALON Coffee Mug Warmer for Desk - Electric Beverage Cup Warmer Plate for Office Home Use with Auto Shut Off - Ideal for Coffee, Tea, Milk, Cocoa by Carolina Whipple

Warning! It's exactly as advertised but such a disappointment. I drink a lot of coffee all morning and was hoping to use my giant mug without having to go back and forth to reheat it in the microwave. The product description says you must use a flat-bottomed mug. I must have thought they didn't really mean it. When the device wasn't working very well, I checked the bottom of my large mug and it had a rounded rim so only the rim/rim was in contact with the device. I then checked my other mugs, of which I have a large selection, and found that none of them would sit flat on the unit. On the high setting, my large cup of coffee stayed warm and not cold, no doubt because there is very little contact with the surface. It can also be a bit more efficient with a smaller cup, but that defeats my purpose. I'll keep an eye on flat-bottomed mugs to see if the device works better with them.