Sun Telecom's SUN-OC-SLT-AP stranded loose tube light-armored (Aluminum Tape) cable (GYTA) construction is that 250um fibers are positioned in a loose tube which is made of high modulus plastic and 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 are stranded around the strength member into a compact and circular cable core; The APL (Aluminum Tape) is longitudinally applied over the cable core which is filled with the filling compound to protect it from water ingress; The cable is completed with a polyethylene (PE) sheath.

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https://en.suntelecom.cn/GYTA-Cable.html