Product review (4 stars): Buy two for both sides
About the vendor:  Great.  Shipped quick.
About Whirlpool:  Seems odd to give a part that is poorly designed by Whirlpool 4 stars especially given it probably fails on every unit.  I would have given it 5 stars but seems awful expensive for a cheap little plastic part that will fail in a few years.  Do yourself a favor and replace both sides instead of cheap old me who is replacing the other one four months later. :(