Product review (5 stars): 5$ of your time vs hundreds for a service call!
I bought my washer and dryer used in 2003(they were ten years old at that point) and I was in college.  Nice Whirlpool set with an agitator.

Flash forward to now (2018, which makes these units close to 25 years old) and the agitator won't spin.  Never having any problems before, i took to the google and youtube, and found out about these Dogs.  Checked all my big box stores to get them, I mean why pay for a service guy to charge hundreds of dollars, but they didn't have them.

Ordered off amazon, took apart the agitator (5 minutes) and had these bad boys in place for the shredded ones, and bam.  This old piece of junk is working like brand new.

Going to buy a set just to have on hand JIC, for 5 $ it was worth the try even though it could've been something more costly for these old units.