For those unfamiliar with the many types of headlight bulbs, figuring out the difference between each one can be confusing. Knowing more about the differences between the various car bulbs and accessories will help you buy the best bulbs for your car.

　　The H4 car bulbs contain two fibers that give them the option of high or low light. The bulb has a three-pronged connection to the wiring unit. Originally produced for European racing cars, these bulbs are very bright and can glow white, blue, purple, or yellow.

　　The H4 car bulb was originally invented for racing. However, for decades its use was mostly limited to European cars. In the US, the H4 car bulb is popular on motorcycles, but cannot be used in cars or trucks due to legal restrictions requiring sealed headlights.

　　Even with these restrictions lifted, the H4 car bulb is still banned from use by US regulators. Twin-filament bulbs are not precise enough to meet the beam pattern limitations of US headlights, as they can easily point upwards and blind oncoming traffic.

　　H4 LED headlights are more expensive than halogen bulbs but last longer. They have a cooler color temperature, appearing in bright white or blue, which is more prominent and makes your car more stylish. Plus, they don't require ballasts to control them, meaning faster, easier to install, and more convenient to use.