I'm not sure of the exact number but I think they're those little #937 bulbs (the little tiny bulbs that you just push straight into the socket)...I've seen them at the auto parts stores in different colors and I'm told AGAIN that there is a double filament bulb like this although I've never remembered seeing one.Mind you, it doesn't mean it does not exist because I didn't look for it but I'm hoping that someone makes this bulb for folks such as myself that would like this effect.
Of course as I think about it, its probably not a big deal to most (including me) but would certainly be something that I wouldn't mind manufacturing and selling to individuals like me that would want this type of bulb
