H1 is a single filament and assymetric rear.
H4 is a double filament for main and high beam in the same bulb.
Don't know what the other is as I don't have them.
I take it you have the projector headlights and aren't talking about upgrading "normal" bulbs to aftermarket HIDs.
yep they are for projector, well after looking some of the threads I am thinking of changing them myself using some of the work people have done on here to more updated ones.
What is the standard fitment on normal GTR headlamps without HID, H1 ?
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