We use them for coffee!
"My wife and I discovered a group of 4 tumblers at Costco some 8 years ago and immediately thought about how annoying it is to be forced to either drink our coffee too fast or have it cool down too soon. Over the years, they got work out, and we tried other brands that turned out to be of a lesser quality, We ended up using those tumblers to the point in which they fell apart! Now we decided to buy a new pair, and I gotta say. . . The new leak-proof technology is proving to be a valuable addition. My wife has trouble waking up every morning, and our daughters spilling her coffee has always been a concern. . . not any more! Oh! Last week I tried the taller tumbler for beer (summers in Florida are HOT!), and it worked just fine, too. I liked the thicker lid, too, as compared to our older models'."
