This is a new Lucas-style British Prefocus (BPF) or P36 base yellow bulb (12V, 45W), correct for Lucas 576, 700, or Ranger lamps. They are foglamp bulbs, which have horizontal filaments, but they will work fine in a spot or driving lamp as well. We have only a very few of these bulbs left, and when they're gone, we cannot be sure of getting any more.