Product review (3 stars): Poor quality part to replace the original poor quality part.  Get ready to buy more.
Looks like the original knob that came with our cook top.  Just a cheap piece of plastic that will probably need to be replaced in a year or 2.  I love the cook top itself.  Why they put on plastic knobs that need replacing every two years is beyond me.  I would have bought a different brand if I knew this would be an issue.  Oh well, what can I do?