Current-light converter

I did not think that there is something. You can digitally convert supplied by satellite receiver electricity into light, which passes this stream. This I understood the fiber cable system. But as the current from the copper wire can be converted into light, to me lay not open up. No matter. It works. Annoying but is also something: Why build the equipment manufacturer is not equal to both jacks, as it TechniStar doing? It does not cost anything extra money and also the additional shipping cost would be unnecessary.