Instruction: Answer the given question by extracting information from the supporting document.

Input:
Question: What is the bottom diameter of the mug?
Document: I am not sure how it even happened, but I just washed this and noticed that I now have a hole a 1mm in diameter and spider cracks going all the way up to the rim of my mug on both sides. It looks like someone literally shot this with a bb gun. I pulled the little plug out of the bottom of it and sure enough, I can see right through the hole. I am still really perplexed by how this even happened.
there's a plug on the bottom, so in theory you could put hot water inside the walls of the mug to keep it warmer for longer; i tried it, not much difference. nice cup for indoors; travel, not so much.
(At 7am in the woods in 35 degree weather... Thank goodness for coffee.) I wouldn't recommend using them to heat up liquid over a fire or a hot plate because both of these types have silicon on the bottom. Good for traction though. Older style full metal thermos may be better for more rugged camping style, but if you're just plonking your mug in the cup holder everyday, this ceramic tumbler is perfect!
I ordered the Trudeau Xpress Ceramic Tumbler simply because it was the only travel mug I could find that was made of ceramic material.Pros: Keeps the coffee warm; isn't plasticCons: Silicone lid is easy to dislodge when picking up the cup, yet a little difficult to put on; claims to be dishwasher safe, but there's a plastic plug in the bottom of the outer layer of ceramic, so I wash the mug by hand (easy)Bottom line: works for me but probably not for everyone.
My wife loves this cup...the bottom at least. The bottom is heavy and holds and keeps coffee warm. She just wishes the top was made of a thicker rubber. It stays on the cup fine but is a little flimsy.
It is going to cool down faster than about any other travel mug.
The "seal" did not work and the mug leaked on first use . A travel mug that leaks is pretty useless.
It can get warm if you put boiling liquid in it but the silicon around the center helps protect your hand from the heat while the mug keeps it hot inside.
Got this for my husband who wanted a ceramic rather than a metal travel mug. I saw reviews talking about the difficulty with the lid, but he didn't have a problem. He really likes it.
The mug seems okay. However as the other reviewers pointed out that the lid leaks. It did not leak the first day however it started leading day 3. Anyone know how fix this?
Answer: The bottom diameter is 2 1/2 inches. It fits in any normal car cup holder. Hope that helps.