There are the following provisions for automobile headlamp: the luminous capacity of low beam headlamp with rated voltage of 12V of motor vehicle shall be more than 1000-1200lm (LM is luminous flux unit: lumen), and the luminous capacity of high beam headlamp shall be more than 1450-1900lm. There are only lower limit requirements in the regulations, but no upper limit requirements. The low beam is 1000lm, and the high beam is 1450lm. In this light flux range, we will feel that the light is very yellow and dark, the road effect is not clear, and the eyes are easy to fatigue. A part of the low beam lamps between 200000 and 250000 are xenon lamps. Ordinary halogen lamps are incomparable. The color temperature of 4300k, yellow in white, and the luminous flux of 3200lm are twice as bright as ordinary halogen lamps. Your eyes feel comfortable. Now most of the 250000-300000 cars have been equipped with double light lens, which is often called Bi xenon lamp. The effect is very good, and it is close to the high-quality configuration of automobile headlight lighting.