Product review (5 stars): standard piece does the trick
This is the piece that strips first if something gets stuck under the agitator or you overfill your washer.  That is a good thing.  Its only a few dollars and is so easy to replace.  I've bought different brands whether GE or not, all seem to be compatible and do the trick.  But you must not overfill your washer.  Keep an extra one on hand.