GYFTY63 is to insert optical fiber into PBT loose sleeve, the loose tube is filled with waterproof paste, the center of the cable core is a non-metal strengthening core, the gap is filled with water-blocking paste, the loose sleeve (and filling rope) is twisted around the central strengthening core to form a compact and circular cable core, and a layer of sheath material is extrudated outside the cable core, and glass yarn is placed outside the sheath as a rat-proof material. Extrude another layer of polyethylene (flame retardant) sheathing.