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The structure of GYXTW optical cable is to insert 250 μ m optical fiber into a loose tube made of high modulus material, and fill the loose tube with waterproof compound. A layer of double-sided plastic coated steel strip (PSP) is wrapped longitudinally outside the loose tube, and a water-resistant material is added between the steel strip and the loose tube to ensure the compactness and longitudinal water resistance of the optical cable. Two parallel steel wires are placed on both sides and extruded into a polyethylene sheath to form the cable.