I bought these coffee mugs because everyone at work who has one raves about them. I wish I had passed. They only keep my coffee warm for one hour but worse than that, the red one got water between the layers and now it will mold and be ruined!! I feel I wasted my money on them and I really regret buying them. I am now going to have to buy another travel mug to replace these and I have only had them for a little over a week.