Product review (1 stars): WARNING: NOT A Waste King Replacement - Solution Below
Yes: this fits a Waste King, but it is nothing like the OEM part that came with your disposal other than being the same size and being black. With the original part, food easily went through the splash guard. With this falsely advertised product, you cannot get food through it. You will have to remove it in order to get food into the disposer.

If you still insist on buying this, then spend another $12 to buy the Tekton crow bar (sold on Amazon). You will need it to ram the food through this splash guard, but be careful not to dislodge the disposer from your sink when using the crow bar. You can find it as: TEKTON 3324 18-Inch Wrecking Bar.

However, if you prefer not using a crow bar to get your food through this rigid plastic food/splash guard, Amazon sells a 3" splash guard that will fit in these small Waste King openings. Get the "Whirlaway 191 & 291 Replacement Garbage Disposal Disposer Stopper Splash Guard." It has the flexible rubber like the original supplied with the disposer.