Reviews of Bosch alternator pulley

I got the bosch alternator pulley kit from ECS that seems pretty complete so am hoping I am good on that front: As to why I have to replace the pulley, the pulley on these alternators is clutched and said clutch goes bad. Symptom being a perfectly fine charging voltage but a chattery sound tied to the alternator light flashing on the cluster. Did a ton of research on here trying to diagnose and this is what I've come-up with as a starting point.

A Bosch alternator doesn't care which Bosch pulley it uses, be it a 70A, 90A, 120A or 150A. The shaft is the same 17mm OD for all of them. What matters is that the pulley matches your belt and application.