Prior to 1976 loudspeaker cables had no identity. They were simply cables. 2 x 0.5 mm 2 was the most usual size, while for high specifications the only alternative was 2 x 0.75 mm 2 . And then there was SUPRA. Since SUPRA 2.5 was introduced, other original ideas have come from SUPRA. The nylon screen, the Swift connector, the stretch-proof multicore cable and the Ply conductor concept, and the Assurance of Cable Directionality are all examples of our forward thinking technology.