Product review (1 stars): poor description, doesn't fit my insinkerator model.
They fail to mention which disposals this works with in the item description. It didn't fit mine (I only needed the metal flange piece) and I have a insinkerator Badger 500. Check my image for models it DOES work with.

I got mine through amz warehouse deals, probably because of the same problem (failure to properly describe product).