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
Basically, cool keyring and stuff, but the bit of the keyring that goes around the loop looked quite thin and today I finally noticed it had dropped off. I'm not fussed like but it might be worth making it a bit thicker though. Just figured it would be worth letting you know.