I just bought Fulcrum racing 3 disc wheels and put Campy centerlock rotors on them. The wheels come with the lock rings. I used a Shimano standard wrench on the lock rings - Park BBT-9. I also have a very old Park BBT-19 cup type wrench with a 3/8" square drive that worked, but not perfectly. I later face sanded the cup type wrench on my vertical disc sander to give the teeth a better grip.

Eventually, owners of Campy or Fulcrum disc wheels will need a special plastic tool to hold the axle internally, while the left hand threaded lock nut on the end of the axle is removed. Without it, you can't remove a freehub body or service the bearings. The tool is a plastic hex wrench. Campy warns not to try an ordinary hex wrench or the thin walled aluminum axle may be damaged.