The 1.25/2.5mm OD Ceramic Sleeve For LC/SC/FC/ST Fiber Connector is a ceramic sleeve used in fiber optic connectors, available in two outer diameter sizes: 1.25mm and 2.5mm, designed for LC, SC, FC, and ST connector types. Made from high-precision ceramic materials (such as alumina), its primary function is to provide accurate alignment for the fiber, ensuring precise fiber mating, reducing insertion loss and return loss, and optimizing optical signal transmission. This ceramic sleeve protects the fiber and enhances the stability of the connector, making it widely used in telecommunications, data centers, and high-precision fiber optic connection applications.