GYTA G.652D Single Mode Optical Fiber Cables for Duct Aerial Tunnels Description: In the GYTA cable, single-mode/multimode fibers are positioned in the loose tubes, the tubes are filled with water blocking filling compound.Tubes and fillers are stranded around the strength member into a circular cable core. An APL/PSP is applied around the core. Which is filled with the filling compound to protect it. Then the cable is completed with a PE sheath.