I got these in today straight from Tokyo Japan.
These are awesome and I highly recommend them to anyone with a 1/32 Semi. The tires are rubber, great tread design Yokohama brand. Rear wheels have a choice of 4 hubs, front 3 hubs. Oh yes even comes with a spare tire (11 total) , rim and a mounting bracket.
I have seen other sizes and wheel styles also. I got the 22.5 's