Quick Injector Question, need quick response

[aidanair]

I'm sending my 740cc injectors tomorrow to Deatschwerks to have them serviced. They say send all relevant parts, so I am sending the injectors and o-rings, but what about the piece that goes between the pintle and the manifold underneath the fuel rail? I am not sure what it is called, do I need to send that to be matched to anything? Thanks in advance.