Custom made, insulated copper and brass metal electrode for any violet ray machine with a 7/16 inch socket diameter. It will fit most antique American violet ray machines, including Master, Fitzgerald, RenuLife, Shelton, Violetta, Bleadon Dunn, Branston, Elco and more. My insulated metal electrode is superior in design and better insulated than the original insulated electrodes supplied with many violet ray machines from the 1920's through the early 50's. It also offers a much larger 5.5 inch grip surface, making it easier for people with big hands to easily and safely hold. Superior insulation insures that the inner and outer tubes are completely electrically separated and will not arc during use. This provides a true barrier between the user and the high voltage output of a violet ray machine. Only the highest frequencies can pass across the insulation layer that separates the inner and outer tubes. The copper sleeve is made of 1/2 inch Type L copper pipe and the inner tube is made of heavy solid brass. One could run over it with a semi truck and it would probably still work!