Prior to purchasing this mug warmer, I read the reviews, and I wasn’t sure if this product could my coffee hot enough. I have a large stoneware mug (16 oz. capacity). Turns out, the mug fits fits nicely on the warmer, and my coffee does stay hot. I made a little aluminum foil cover for my coffee mug, to keep a “film” from forming on the top of my coffee (I use heavy cream in my coffee). Not only does the foil cover keep a film from forming, it prevents heat from rising from the mug. My coffee stays nice and hot for as long as it takes me to finish it, which can take an hour or more. When my coffee is partially gone, the mug warmer makes the remaining coffee almost too hot to drink! Get this warming plate and make a simple foil cover for your mug; your coffee will stay hot! Another thing: There is no heat buildup under the warming plate. I have it sitting directly on my desk top and the wood feels barely warm from the product.