AZ... well, a lot of parts are 'recycled'... and not by true 'professionals'... sometimes to 'minimum acceptable level'... by experience, not opinion...
I go to a local 'old time' part supplier and buy 'new'.. especially on important items like 'brakes'...
AZ also bumps up price for items like windshield wipers, etc.. that are made by others only as 'new'.. in the 'bubble packaging'..
One example.. I bought a "grade 8" bolt from AZ for my HD... as I was torquing, the bolt head sheared off.. on inspection there was a "void" between the shank and head.. It was doomed to fail... had it failed when I was 'running' the HD, it would have been very, very ugly..
Peace and Blessings..