The construction seems good. The problem is that the lid has an opening to sip liquids, but there's no sliding cover or anything else to make sure the liquid doesn't spill. I would also think that liquids are far more likely to cool off more quickly than they would otherwise. I'm doubly sad because this was meant to be a gift and I don't have time to exchange it. There are better designed thermos/tumblers for this price. Finally, even though black wasn't available when I purchased the item last week, it's suddenly available again. I wished they had at least left black as an option and listed it as sold out if that was the issue. I feel like I missed twice on this item. The same comments apply for the Assistant Principal thermos purchased from the same company.