The fiber , 250m，are positioned in a loose tube made of a high modulus plastic. The tubes are filled with a water-resistant Ring compound.A steel wire，sometimes sheathed with polyethylene (PE) for cable with high fiber count, locates in the center of core as a metallic strength member. Tubes (and Hers) are stranded around the strength member into a compact and circular cable core. An Aluminum Polyethylene Laminate (APL) is applied around the cable core, which is filled with the Ring compound to protect it from water ingress. Then，the cable core is covered with a thin PE inner sheath.After the PSP is longitudinally applied over the inner sheath，the cable is completed with a PE outer sheath.

　　Good mechanical and temperature performance

　　High strength loose tube that is hydrolysis resistant

　　Special tube filling compound ensure a critical protection of fiber

　　Crush resistance and flexibility

　　The following measures are taken to ensure the cable watertight:

　　1.Steel wire used as the central strength member

　　2.Loose tube filling compound

　　3.100% cable core filling

　　4.APL moisture barrier

　　5.PSP enhancing moisture一proof

　　6.Water-blocking material