This is a genuine Lucas H4 P43t base (12V 60/55W) xenon bulb, 30% brighter than a regular LLB472 halogen bulb (but same wattage), imported from the UK.
Lucas part number LLB472X, interchangeable with part number 9003.
It is correct for our Lucas H4 and PF700 headlamps, among others; see Related Products below.
We also carry normal halogen bulbs (LLB472) and blue bulbs for the same applications, as well as several other headlamp bulbs; some can be seen in Related Products below.