If your lights look like this:
https://www.eeuroparts.com/Parts/594...enon-30764402/
They are genuine Volvo Reflector Xenon and need "R" spec bulb.
If they look like this:
https://www.xdalys.lt/en/28013726
i.e. black plastic inside then they are halogen lamps with a HID kit fitted - not good really.
If they look like this (which they shouldn't) :
http://erievovo.com/shop/index.php?r...roduct_id=1366
These are the projector based Bi-Xenon ABL (bendy) lamps that require a "S" spec bulb.
Also - I *THINK* that the Reflector based Xenon's take a D2R bulb (not D1R), whereas the Projector Bi-Xenon/Active need a D1S. You cannot mix D1 and D2 as the difference is the ignitor system - getting it wrong will either mean it doesn't work at all or you may damage your ballast.
A good parts website might help confirm - please don't take my word for it & check before splashing the cash!