4-core cable is to have the same light as the transmission speed communication cable, 4-core cable wide bandwidth, transmission speed, confidentiality, anti-electromagnetic interference, good insulation, long life, good chemical stability. 4 core cable commonly used models are divided into: GYXTY central tube. GYXTW 4 250μm core fiber optic cable structure is set into the high modulus material loose tube, inside resistant filling compound. Loose layer of double-sided coated steel casing topical (PSP) vertical package, plus water-blocking material between the strip and loose tube fiber optic cable to ensure compact and watertight, placed on both sides of two parallel steel wires extruded polyethylene Ethylene sheathed cable. The structure sucked GYXTY 4 250μm fiber core cable set into the high modulus material loose tube, loose tube filled waterproof compound 6. After attaching the outer layer of loose tube water-blocking layer placed on both sides of two parallel wires extruded polyethylene sheath into the cable.