Product review (5 stars): Fits my Jen Air stove's fan knob perfectly and easy installation
The number on the bottom of the knob is 5D02, as someone else mentioned. This seems to be the most important part of the information, I wish it was included in the product description or title, not just in a review. The part number actually was different for my original one.

Fits my Jen Air stove's broken fan knob perfectly. Basically no installation was required. I pulled out my old broken one, snapped on this new one, and voila. Works perfectly.