“Do I have dual-beam or single-beam headlight bulbs?” The answer to the question often brings confusion, but it’s surprisingly simple:
The term “Dual” and “Single” refer the function of a headlight bulb. A dual-beam headlight bulb has dual functions; The bulb creates a low and a high beam – “dual beams” in one headlight bulb. A single-beam headlight bulb has a single function; the one bulb creates only one beam (either low or high beam individually).
HOW TO IDENTIFY DUAL BEAM BULBS:


HOW TO IDENTIFY SINGLE BEAM BULBS:


Just remember if you’re looking at an LED headlight bulb or HID conversion kit and you’re unsure of the difference, just remember to focus on the bulbs themselves, not the headlight housing. Do you have a bulb that does 2 beams in 1 bulb or 1 beam in 1 bulb?
If I have a dual beam assembly and only my low beam works, can I put a single beam LED bulb in it and it emit light similar to a high beam?