ZNR stands for Zinc–oxide Non-linear Resistor. Panasonic invented the ZNR Surge Absorber in 1968 and was a pioneer in the use of Zinc Oxide as a Surge Absorber. Panasonic ZNR Surge Absorbers are the top brand of Surge Absorbers and have been for over 40 years. ZNR devices are used to protect electronic equipment against voltage surges. The equivalent electrical circuit of the ZNR would be back-to back zener diodes and a parallel connected capacitor, that’s three components doing the job of one ZNR. ZNR Surge Absorbers can save board space and cost.