Great cups
Have successfully shlepped these in the plane, to the beach (great all-inclusive cup solution, even if they won’t always fill directly into it) , in the car, used as emergency measuring cups (yup, the lines are volumes! lol) and generally loved them for both hot and cold bevvies. Haven’t done any scientific research on exact temperature over time, but there have definitely been ice cubes remaining the next morning and coffee’s never gotten cold before I’m finished. Just remember to open the lid before you put them on! Don’t stack quite as tightly as the plastic ones, but that should’ve been apparent if I’d looked at the pics :)