Originally Posted by tlp
Isn't it more than just a spacer? It's an adapter as well. The centric lip is bigger to accept the larger center hub bore of the BBS GT4 wheels.
Ralf feel free to chime in.
You are right Terry.
The GT4 Motorsport rims have a 77.5mm center hub and need spacers to be installed on the 72.5 hub of our stock M3. The GT4 uses 5mm spacers in the front and 15mm spacers in the rear.