This mug has two main problems. First, the description says the mug is 4 inches tall. The cup is actually 4.5 inches and doesn't fit our espresso machine at work. The description also states that it will keep you warm "up to three hours". I'm not sure how they came up with that number, but even after preheating the mug with boiling water, after an hour my coffee was still at room temperature, even with the lid on. The mug will warm up when you hold it with a hot drink to the touch, not so warmβ¦