Most people think that a 9003 bulb is just a high beam, but it can actually be used for both high and low beams. The reason why it’s called a 9003 bulb is because of the way the filament is wound. There are three different ways to wind a filament, and the 9003 is wound in such a way that it produces more light than other bulbs.
So, if you’re looking for a bulb that can be used for both high and low beams, then the 9003 is a good choice. Just make sure to get one from a reputable brand so you know it will last.