Fiber optic patch cords are composed of a fiber core and an outer PVC material package. The core of the fiber optic patch cord is quartz glass, which is usually a double-layer concentric cylinder with a small cross-sectional area made of quartz glass, which is brittle and easy to break. There will be a cladding on the outside, and then a layer of leather conduit on the outside. The above constitute the fiber optic patch cord.