Just FYI, here’s a bit of optical fiber cable for telecom applications like, you know, the Internet. It’s a tube:
Loose Tube Optical Fiber Cable
WLC’s loose tube cable consists of acrylate coated fibers placed loosely in a gel-filled thermoplastic tube 12 fibers are respectively colored. Required number of loose tube and fibers are stranded around a metallic center member, followed by water blocking filling and aramid yarn for flame-retardant cable only.) Then a black polyethylene inner sheath is applied. A water blocking tape shell is applied over the polyethylene inner sheath. The outer jacket is LAP or LSP, or FR-LAP. The application is good at urban junction & long-haul communication. Please call for further details.
Now you know.