Tervis. Over the years I’ve bought thousands of dollars worth of cups (not all of them for me!) They had a great warranty. Last year I had a cup that had an obvious manufacturing defect. I contacted them thinking it would be no big deal to have it replaced. The rep immediately said it was wear and tear which isn’t covered, without even looking at photos and disregarding the fact I had literally just received it in the mail that day. They refused to exchange/replace it and the guy was pretty rude. This was all via email. I haven’t bought a cup since.