Product review (3 stars): They're cheap but workable.  Here's the size/shape information.
These are replacing an identical set with the brand name Lux (also sold on Amazon).

They fit my stove, an Imperial brand gas range with pilot light.  It is at least 50-60 years old (It's a cheap range in a rental I moved into 35 years ago, which I've kept because it's far better quality than the cheap ranges of today) .

Neither this nor the description of other knobs include the diameter of the knob-shank it fits (GRRRR!), and they were the wrong size for some other reviewers.  So here some useful info.

  These fit over a "D" shaped knob-shank. The diameter of the shank on my stove is about 8mm. They're ever so slightly
  loose, so if yours is 9mm, that would probably work.

  The black and white adapters in the picture fit the same shanks, but raise the knobs to different heights.

Are they pretty? No. They're cheap looking.  In contrast to the reviewer here that likes the metal bands, I think they're pretty flimsy, and would prefer the knobs to be all black. (To each his own. I'm glad they are pleasing to him.)

Are they good quality? No. The first set I bought lasted 3-4 years, and then started falling apart.  The inserts crumbled and the outside cracked--they don't seem to be able to withstand a lot of heat.

They do have the advantage of being a relatively small cash outlay, though I believe they are over-priced for the quality.  I wish I'd been able to find something of better quality--happy to pay more.