LC-ST SM/MM/OM1/OM2/OM3/OM4 DX 2.0/3.0 PVC/LSZH Optical Fiber Patch Cord Optical Patch Cord is jumper wire from device to optical fiber link, usually used to connect optical transceiver and terminal box. Optical Patch Cord (also called optical fiber connector) is fiber cable assembled with optical connectors at both ends to get through fiber active link. Optical Fiber Patch Cord/Cable is similar to coaxial-cable just without reticular shielding layer. The fiber center isglass core of optical propagation. For the multimode fiber cable, the core diameter is 50μm~65μm and thin as a hair. But the core diameter of single mode cable is 8μm~10μm, the outside of it is glass jacket of which the refractivity is lower to keep the fiber within core.