Product review (5 stars): Compatible with my Model 777, works great.
Fits perfectly in my 12-year old insinkerator model 777SS-1, replacing the old removable baffle and the lower baffle. Had to cut away the old lower baffle (easy one minute job with a serrated kitchen knife). The old baffles were gross so I'm glad the new one is anti-bacterial. Looks like new and works perfectly. As others have noted, it does slow the water flow a bit so about an inch of water accumulates while the faucet is running, but that's not a problem for me.