Kate Alta wrote a review of Hydro Flask 10oz Rocks Cup on September 18, 2017
Familiarity: I've used it several times
So I was on the Grand Canyon in June and I made a margarita with the last of the cubed ice and put it in this bad boy. The next morning it STILL HAD ICE IN IT. Which wouldn't be that impressive, except for it's like 95 degrees all night down there. So anyways, I used the rest of the margarita to brush my teeth, since dumping out the ice felt wrong. Moral of the story: don't brush your teeth with tequila, do buy this cup if you want to pass un-melted ice cubes on to your grandchildren.