You trim and size the kit to fit your own body. I assume you are talking about the arming suit size? If so, that's just the black undersuit. I hope that answered your question.
All righty. I finished my blaster.. so here it is. I did not get it as accurate as I wanted it, but I needed it finished. I also decided that in the future I will build a better one.
While being frustrated with sizing I took a break off the armor and finished my blaster. Please note that I want to make a more accurate one, but that will have to wait for later.