A wheel PCD is made up of the number of studs that hold your wheel on, and the diamater in mm of an imaginary circle that goes through them all
So 4 x 100 would be 4 studs with a circle diameter of 100mm.
If you're not sure of the PCD of your car, just ask us and we'll be happy to help
I've been through a couple of sets of these pads on my E36 track car, for the money i'm very impressed.
Once bedded in (important!) they provide a very positive and firm brake pedal feel and continue to do so throughout a considerable amount of time on tracks requiring heavy braking.
Superb braking power, fairly easy on discs, not too dusty, give great braking confidence, excellent from cold.
Other than the fact they are quite noisy (to be expected with any track pad) The only DOWNSIDE to these which I feel is quite a let down is they don't come with metal retaining clips to secure them inside the piston and as a result the pads rattle against the caliper. I have purchased some sticky back brake shims which solve/reduce the noise although they don't last long until they need replacing.