The mug is metal, with the handle and the bottom coated in some rubber.
The cover lid is plastic, has a hole for drinking which can be also covered, and it's threaded.
Which is nice, except that the cover of the drinking hole is not sealing, so some care needs to be taken.
It turns out I use this stuff very little, and I have others, so it's for free.

The other thing is a plastic container with a plastic lid, threaded.

Price: free; buyer picks up (Palo Alto area).