SON-E lamps (elliptical sodium vapour lamp) is a gas discharge lamp that uses sodium to produce light via wavelengths. They are often used in industrial lighting and are one of the oldest types of gas discharge lamp there isTo notice the lamp should have a triangle with the letter I. If there is no lamp in the luminaire currently, look at the gear tray and see if there is an ignitor wired into the circuit. In traditional lighting magnetic ballast circuits, you should have a ballast, capacitor and ignitor. If no ignitor is present in your circuit, you need a lamp with an internal ignitor.