Duplex Fig-8 cable uses a single Φ900μm or Φ600μm tight-jacketed optical fiber as the optical transmission medium, covered with a layer of aramong as the force strengthening unit, and extruded with a layer of polyvinyl chloride (PVC) 、low smoke halogen-free material (LSZH, low smoke, halogen-free, flame retardant) and Polyurethane（TPU）sheath.