This is the bolt pattern, also referred to as the stud pattern or PCD (which stands for pitch circle diameter). The PCD is measured in mm from the centre of one bolt hole to the centre of the next hole but one as shown.
For example with 4x100, 4 is the number of holes and 100mm is the measurement.

What is wheel PCD?

4x100

PCD or Bolt pattern

Here's a list of current 4x100 wheels in the Cades range.4x100 is the bolt pattern, also referred to as the stud pattern or PCD (which stands for pitch circle diameter). The wheels will only fit cars that require this wheel spec. Some popular cars are:

VW Golf MK1, MK2, 4 stud MK3, Polo, UP
Vauxhall Corsa all 4 stud models
BMW Mini, and 3 Series (E30 model)
Mazda MX5

Call us to see if it fits your car if it's not on the list.