Product review (4 stars): but it wasn't always easy to find them locally
I have used a number of splash guards in the past, and found that they have a limited lifespan. I tried to replace them whenever anything started splashing back, but it wasn't always easy to find them locally. Several months ago, I purchased a brand name Waste King replacement. It was more expensive than I felt was reasonable, partly because it came with a stopper that I didn't need. It also seemed far more durable than any splash guard I'd ever used. The only problem with it was that it was so stiff that it was difficult to get food through it, especially without a pusher. As time went on, nothing changed. This is the first time I've replaced a splash guard that worked as well as when it was new.

This splash guard works perfectly. It cost more than I would have expected for a generic substitute, given the price of the name brand, but it's certainly affordable. I don't know how long this will last, but by nature these are not long lived products.  Although my disposal is a Waste King, the one I ordered and received was "Style: Whirlaway and Sinkmaster" and "Size: Replacement Splashguard." It was pictured correctly as what I needed. The guard itself is a small fraction above 3 inches, making it an appropriately snug fit for a three inch orifice.