Those are supersingles. We put those on the single wheel 3/4 ton and 1 ton trucks. Regular 22.5s are 8.25" wide and some are 9" wide.
Are they 300 for a set or per wheel?
I have a couple of customers I have sold the supersingles with a 25'dc offset and they have run them on the rear of their duallys instead of the dual wheel setup.