Rebel SOS-9 - Questions for Beginner

[jbocook0001]

I just received my Rebel SOS-9 9mm suppressor and I have several questions. Unfortunately, the dealer did not know a lot about them, that was disappointing, so i thought i would reach out to you guys.
i'm trying to determine if you have to run the bottom piece w/ the spring? or can you take off and it has an adapter to go on and will attach to threaded barrel.
also, it says 9mm and that is what i want, but can i run other calibers through it?
for the most part it seems pretty cut and dry, but the part with the spring and why it came with two threaded attachments (one goes on end piece, one does not, both are 1/2 x 28) and range of ammo that i can run throught it are my main concerns.