I love this mug! One of my biggest problems with drinking coffee for my entire adult life has been not being able to finish my coffee before it gets cold, and I am constantly reheating my coffee in the microwave. It's maddening! That problem has been solved with this mug! The coaster is too convenient, and the coffee stays hot for a long time. Longer than it takes for me to finish a cup of coffee! Thank you Ion and HTC! Love it!