My daughter bought the travel mug for me for my birthday. Honestly I left it in the box thinking I would never use something so expensive to just drink coffee. After a few weeks of her asking I broke down and opened it. The mug is amazing and I am hooked. It keeps my coffee hot and is a breeze to clean. I have knocked it over and the seal is solid. I love it. I think the mug is genius and have recommended Ember to all my friends who love hot tea and coffees!