Product review (5 stars): Works great, inexpensive
My Sears washing machine has a "turbo" high speed agitator speed that eats up feed dogs but washes clothes better.  Since these feed dogs are cheap I bought several packages.  Just be careful loosening the clip piece that holds these down as it's easy to damage it and then you'll have to replace the larger part, otherwise, these feed dogs seem to restore full agitator function.