Extralink MICROCABLE is a fiber optic cable designed to be used in microducting. 12 G.652D type fibers were used. The construction of the cable is 12 tubes twisted around a central FRP rod, which is a strengthening element. Additionally, the cable is filled with Water Swellable Yarn - a polyester yarn swelling in water which prevents water penetration. The cable's outer coating is corrugated for easy blowing of the cable into the sewer pipe.