OM2 ST ST Fiber Optic Cables | Plenum Duplex 50/125 Multimode Jumpers. OFNP Plenum rated multimode fiber patch cable assembly with orange colored, self-extinguishing, 3mm outer diameter jacket. Corning 50/125u fiber cores terminated with duplex 2.5mm stainless steel ferrule, push and twist, ST fiber optic cable connectors.