The EXFO EUI-89 FC Connector Adapter Cap is a versatile accessory designed to enhance the functionality of all EXFO OTDR models. This twist-on adapter cap simplifies the process of switching between fiber connectors, allowing for quick adjustments as needed. With compatibility extended to the EXFO FiberBasix 100 and 500 Series fiber optic light sources, it provides a reliable solution for users requiring the FC connector type. Effectively replacing the original adapter, the EUI-89 ensures seamless integration and optimal performance across various testing and splicing tasks, making it an essential component for professionals in the field of fiber optics.