Bulb type…

[Ruairidh Dunford]

Can anyone tell me the bulb type/code for these please?

       

6v 21/5w twin filament parallel pins

Thank you.

[Andy Bennett]

I think that's 15D, the 15 being the diameter in mm. But please wait for others

[John Cornforth]

Hi

I think that's a BA15d base. The staggered ones are BAY15d

https://www.classicbulbs.co.uk/products/...bulb-b383b

Please double check, it's a bit of a minefield !

[Andy Bennett]

I was just about to add that having done a bit of searching and agree BA are parallel pins and BAY offset

[Ruairidh Dunford]

Thank you, John and Andy - very helpful indeed.

Ruairidh

[AustinWood]

I suspect its 25/25 Watt headlight bulb. As mentioned already its 15d bayonet fitting.

[Tony Griffiths]

It's a slightly unusual bulb in that the pins are parallel. Most stop/tail bulbs have offset pins, so the bulb will fit in one direction, allowing the correct tail-light and stop-light contacts to be made. The earth return is through the body of the bulb. 
Some single-filament bulbs have a double base contact, one for the live feed, the other for the earth.  
One of the problems in ordering bulbs is that the sellers often miss out important information or put up useless pictures. e.g this retailer, while this one has all the data correct

[David Stepney]

I had a similar problem when I replaced my rear lamps for the pattern L582 type lamps. The lampholders were for for parallel pin type bulbs and all I had in stock were offset pin bulbs. Got over the problem by filing the upper pin off.