Product review (4 stars): Spladh Guard good but Sink Stopper unneeded.
The Splash Guard is okay and does the job quite well.  In fact it did it a bit too well until I cut the tabs to enlarge the center hole because the original hole was so small it inhibited the sink from draining at a reasonable speed.  Enlarging the hole to the size of a nickel or even a quarter-dollar and extending the short slits between the segments to the same diameter as the longer ones increased the flexibility to permit easier entry of waste into the disposal unit and resulted in a big improvement. This was very easily accomplished with a pair of scissors. As for the Sink Stopper I had no need for this item - the original which came with the waste disposal unit seldom wears out as does the Splash Guard - but I couldn't buy the Splash Guard without buying the Sink Stopper as part of the set.  Far better would have been to package 2 guards in the set to provide a spare because the guard seems to have a limited life expectancy which I estimate at about 2 years.