Description
Three color 6″ x 8 3/4″ ad that discusses the fact that using AC Spark Plugs will allow your car to have “Harmony under the hood”. The ad lists several reasons, starting with the “patented Coralox Insulator”, for the harmony present in cars equipped with AC Spark Plugs. It mentions that this is the “finest insulator in spark plug history” and combines with the other features to make this plug unbeatable.
Source: February 1949 Popular Science.
