Volvo 940, Year 95, Non-Turbo, 8 valves

I want to replace the injector seals because I suspect there may be slight vacuum leak at the manifold end. I checked with some of those sites like GAPA, Volvo OEM, Importec that carry this part. They have a picture of the kit that shows one yellow cap, three O-ring and a grey color spacer like plastic. The part number at these sites is 1 287 010 704

My injector has only 2 O-rings, one at the fuel line end and the other at the manifold end. Why the 3 O-ring in the kit?

The FAQ said that there is a cap at the spray end of the injector, which I suppose that is what the yellow cap is for. However, when I told out my injector I could not see any cap on the spray tip end, all 4 of them.

Does this mean the kit is not the right one for my car?

Also what is the grey color plastic (shaped like a large O-ring) for?
I can't find anything on the injector that resembles that.

Since I'm not in the USA and I like to order the kit if it is the correct one, can someone confirm that the kit I just described is the correct kit for my car. I don't want to end up buying the wrong kit and not able to return them.

Thanks for the confirmation and any advice.

Laozong