Product review (5 stars): Absolutely perfect in looks and fit for 1990 Jenn-Air C236 gas cooktop!  love them!
I can't believe how absolutely perfect these replacement knobs fit my old Jenn-Air gas downdraft cooktop from 1990 model C236W.  They are identical in looks, the stem that fits down over the metal rod is the exact D-shape as the original, and the exact length.  Same color and shape, the only difference being the original knobs are a little thicker on the backplate, which has no effect on how the knob fits or works.  In fact they look better, just a little more streamlined being a little flatter.  So happy to be able to replace the originals which were looking pretty rough with paint chipped off the corners.