Most fiber optic ferrules use zirconia ceramic. This material is known for being precise and reliable. The ferrule does not scratch or break, even after many uses. Clean and check your fiber connectors often to keep signals strong and stop problems. Optical connectors are used to connect optical. Two types of ferrule materials are commonly used in the manufacture of fiber optic connectors: zirconia ceramics and composite plastic polymers. A ferrule's job is to hold the fiber core in perfect concentric alignment while maintaining extremely tight tolerances according to IEC 61755, IEC 61300. Ceramic ferrules and sleeves are often used in optical connectors, attenuators, fiber stubs, and other optoelectronics requiring low signal loss.