File:Http://i1010.photobucket.com/albums/af225/allstar cine/IMG 1239-1.jpg Rosettes are a great way to mount things together that should have their orientation be changed quickly and easily.
Unfortunately (like it is quite common in cinema technology) every manufacturer has established his own Rosette standard meaning that parts from different manufacturers don't fit together.
This page tries to assemble the essential specifications of all the different Rosette Systems:
60 Tooth Rosette with M6 internal thread.
Outer Diameter: 28 mm ? (needs verification)