Light and visibility are critical to your safety on the road. New cars now have either Xenon or LED headlight bulbs. However, halogen lights are still the most common type, found in about 80% of all cars. They emit a high-intensity yellow-white light and are very inexpensive to produce. Common bulb fittings include H1, H3, H6, H4, and H7.

　　'H4' means they are dual-filament lamps, also known as Hilux bulbs, which means each bulb contains two filaments. This allows them to be used as high and low-beam lights, with one filament for each beam. They are designed with only one light base plate.

　　The H7 assembly is a monofilament headlight bulb. This means you need two H7 bulbs for each headlight, one for each beam. The reflectors are positioned according to the filaments in each bulb. If your vehicle is compatible, each headlight will have two base plates.

　　It is not possible to replace an H4 bulb with an H7 bulb and vice versa because the difference is only too big. There are two main reasons why they are not interchangeable:

　　There are different types of base plates, so you can't try to plug the bulb into a different bulb socket.

　　The headlight reflector is specifically designed to match the position of the bulb filament. The positions of the H4 and H7 bulbs are different, so it will affect the low beam and high beam.

　　Haining Suez Car Lights Co., Ltd is a car headlight supplier, the main products are H4 car bulbs, etc. Welcome to consult!