The technology for blocking 3rd harmonic current flow in an electrical distribution system. This technology is totally passive. It utilizes a tuned resonant tank circuit that has almost infinite impedance at the 3rd harmonic, but relatively low impedance at 60 Hz. By preventing harmonic current flow the technology renders the entire distribution system free of 3rd harmonic currents. The 3rd harmonic currents are not absorbed or dissipated as heat…they are never permitted to flow in the first place. (see: Current Distortion, Harmonic Filter)