Tumblers
Tumblers without a handle, for on the go and in the cup holder. Almost all are double-walled, so your tea stays hot until you have time for it. Some can be engraved.
Features of tumblers
A tumbler has no handle, and that is why it fits where a mug does not: the cup holder in your car, or a side pocket of a backpack. You hold it in your hand, so the double wall does double duty. Hot stays hot, and your fingers do not notice any of it.
Sizes vary widely. An espresso tumbler is around 120 ml, a lowball 295 ml, and the largest tumblers go up to almost 900 ml for anyone who wants to get through half a day on one fill.
The lid determines the use. A sliding lid is for drinking quickly, a straw lid for cold drinks. Many models are stackable.
If you still want a handle, have a look at the mugs. The full overview is under mugs and tumblers.