If your car has a manual tensioner on the serpentine belt like the 3.3 in my Concorde, do not run Napa belts. They are a waste of money.
I could not get one that did not squeal and had to splurge on a Goodyear Gatorback belt at Checkers. So far no squeals. I haven't even had to retension it.
Just trying to keep others from wasting money like I did on mine.