High Quality Optical Digital CableConstruction of the OPT-1 begins with medical-grade light conducting fiber. The fiber is then encapsulated in a thermal barrier that inhibits heat warping of the light-carrying fiber. A mechanical damping outer barrier is also applied to further protect the cable from damage. The ends are then cold-polished helping to further reduce the incidence of reflections.. With such excellent light transfer characteristics, the result is a sound with is full, relaxed, and transparent.