The fibers, 250¦Ìm, are positioned in a loose tube made of a high modulus plastic. The tubes are filled with a water-resistant filling 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 fillers) 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 filling 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.

Characteristics
Good mechanical and temperature performance
High strength looes 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
Steel wire used as the central strength member
Loose tube filling compound
100% cable core filling
APL moisture barrier
PSP enhancing moisture-proof
Water-blocking material