The ISO Universal Flange System covering the nominal bore sizes from 63mm to 630mm is herein called the ISO (International Standards Program) Flange System. The interface dimensions of this system are defined by this organization. The flange family is called by various names; i.e. ISO Pneurop, ISO-PF or ISO-K by European manufacturers. The picture below illustrates and assigns descriptive nomenclature to components of the flange system. The descriptions are different from the small ISO-KF flange systems to avoid conflict with their components.