Optical fibers are housed in a loose tube that is made of high-modulus plastic and filled with tube filling compound. Two steel wires are placed in parallel outside the tube, and a round-shape PE sheath is extruded.
光纤装在由高模量塑料制成的管中，并填充化合物。在管子外面平行放置两根钢丝，圆形PE护套。