Product review (5 stars): A third the price as at the parts store - for the same exact part!
Factory part, good quality. Fits most brands of gearbox-type washing machine. Put the model number in partselect.com to see if this will fit. If your washer sounds OK and the tub tries to spin up but can't, likely it's a slipping clutch, and this will fix that.
Replacement instructions at youtu.be/tVc6SZ2DD4U - easier than it looks, just make sure the tub is empty and drained first.