Two required per vehicle, one for each fan assembly.
These resistors are manufactured by KRAH, a well known German supplier.
They are NOT a Chinese knock-off product.
You can buy two of these for less than a VW dealer charges for only one resistor.
For early 5 cylinder models, these are located under each headlight
Later models VR6 models, they are located behind the front bumper
If your cooling fans are only running at the highest speed, then the resistors are shot.