A technology designed to improve power quality in home and office environments. Easy to install. Simple plug-in design. Use as many as needed for your situation. (Meters are also available.) The STETZERiZER ï¬lter is designed to ï¬lter harmonics and other high frequency current (trash) from the electrical environment, thereby reducing the potential for leakage into the human environment from televisions, computers, variable frequency drives, energy-efï¬cient lighting, etc.. Designed by Graham Stetzer. --- We recommend a minimum of 4 filters even for a small place. In order to exactly measure your situation you need a Stetzerizer Meter.