The automotive bulb number 4000 is a single beam lamp that utilizes Halogen technology. It has one filament and a P22d base. The nominal power of this bulb is 12 volts and 35 watts. It is commonly used as a replacement for headlights and fog lights in vehicles. The bulb is designed for use in reflector headlights and has a lifespan of approximately 2 years. The name 4000 indicates that the bulb is part of the H4 series and has a wattage of 35. The bulb produces approximately 1500 lumens and has a color temperature of 3200 kelvins. It is interchangeable with other bulbs in the H4 series, such as 9003 and HB2.