depending where you are located you can shop a few different mail order houses - FCP Euro, EEUROPARTs, IPD USA, AZ AUTOHAUS are just four that I've used on both coasts (FCP and Eeuroparts are here in CT) IPD and AZ are on the west coast. If you decide to go Volvo Genuine, Tasca Parts has the best prices but the others ship faster. Just need to look at your pressure regulator to get the right model as there are two part numbers - one has two threaded fittings the other has three.