Ferrule hole concentricity – The shape of the ferrule's hole bore must be round. A fiber optic connector is a mechanical device used to align and join optical fibers, enabling light to pass through with minimal loss. Different connector types have different characteristics, different dvantages and disadvantages, and different performance cylinder. Ferrule hole diameter – The ferrule is arguably the most important component in a fiber optic connector. If not, you. Lateral offset of the cores of the fiber can be caused by fibers with offset cores or the connector. The connectors can be put on patchords, pigtails or components with single-mode (SM). SC connector is built around a long cylindrical 2.