The NZ IK-HE is also available in pure copper or brass. Not more than 10
filters have been produced in this precious material. The dimensions and
configurations of performance correspond to those of the IK-HE version. One
net filter of this type of construction weighs 13 kg. In addition, these
exotic filters are equipped with silver plummet and Mu-Metal (magnetic
shield for protection from radiation). The copper or brass case of 12 mm
thickness grants shielding against radiation of all kinds. The correct
polarity of phases is indicated by a blue or red LED-signal at the exit side.

This optimum preparation of current produces a distinct increase in quality
of music reproduction at all audible levels of frequency.