The small flange connection developed by Leybold has become the basis of the international standard for vacuum technology.

The ISO-KF connection (to DIN 28 403 and ISO 2861) permits rapid fitting and replacement of components in vacuum systems. It consists of two symmetrical ISO-KF flanges , a centering ring with O-ring gasket and a clamping ring. High vacuum tight ISO-KF connections can be made without the use of tools simply by turning the wing nut of the clamping ring.