Product review (4 stars): Well worth it to save on a service tech's labor charges if you are handy with a screwdriver.
These four little agitator pieces are well worth the money and only less than 1/2 hour time to install.  I highly recommend buying these and doing the replacement yourself vs paying a service tech to do it, if you are the handy type.  Just google how to repair washer agitators and follow the videos ("replacing Washer Agitator Dogs").  I actually only spent about 15 minutes to replace these but it's because I am very handy and this is my third time doing it between two washers in the last 20 years.  Save$100 hiring a service tech.  My 20 year old washer is back to working as normal again.