The XLR connector is also known as Canon Port because Cannon Electric Company, founded by James H. Cannon, is its original manufacturer. Their earliest product was the "cannon X" series. Later, the product was improved by adding a latch. An "L" was added after the "X"; later, a rubber seal (rubber compound) was added around the metal contact of the connector, and then added an "R" after "L". People combine three capital letters and call this connector "XLR connector".