I love the flip and go stainless mug, it is the perfect size, I'm not a coffee drinker so I really don't know how long it keeps things hot  but I can say that it keeps things cold for 7 plus hours.  I set up at a flea market for over 6 hours and I still had ice when I left  7 hours after filling it up.  Best mug I have ever owned and used.  Did nit disappoint.