超碰最新免费,91久久国产露脸精品,久久综合91,国产91在线免费视频,一区91,91精品国产综合久久福利,久福利

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.