Product review (5 stars): A great replacement.
NOTE:  You Do Not Need This With a new Waste King disposer!

So, this works and fits just great with my 1HP Waste King disposer, in fact I like the design of the stopper better than the original one...

However... I bought it at the same time I bought my new Waste King disposer from Amazon because the description and some reviews made it unclear if this part was included or not... so I ordered it just in case.  It IS included, so I didn't need it, but now I have an extra in case I ever need it.  (For the price, it wasn't worth returning)