Genuine Lucas 6v 4 Watt Pilot bulb (and possible speedometer/rev clock bulb): Type LLB293, from the Lucas Classic range. As fitted to most Norton single cylinder models using Lucas (or proprietary) electrical lighting systems from the 1930's - 1960's. Price is Each
This is a small single filament 6 volt bulb, and is of the type found in some smaller or early type main headlight pilot bulbs. It is also of the type commonly found fitted to Smiths Speedometer and road bikes fitted with rev clocks.
The diameter of the metal part of the buib (i.e. where it fits into the headlight/speedo bayonet) is - 9.1mm, and the bayonet prongs are parallel.
As far as I can tell, these small bulbs are identical to the Lucas 2W Instrument bulb (Item1163), other than these are of a slightly higher wattage - 4 Watts instead of 2 Watts. The Lucas description indicates that these are pilot bulbs - rather than the 1163 Item (which are described as Instrument Bulbs) - but I would expect they could be interchanged if you wished to use a stronger or weaker bulb.
similar to original specification. However, we can supply by special order both 12 volt and high lumonisty modern 6v LED bulbs from Lucas as well. Enquire for details and price - email firstname.lastname@example.org
These bulbs come to us packed in a box of 10. When buying a single bulb - we will pack each bulb in bubble wrap and sealable bag to protect it in transit. If you buy a full box of 10 (enter 10 in the Qty field when ordering) - we will apply a 10% discount on the box of bulbs when we send the final invoice, and they will come packaged in the Lucas box.