needle

I don't how to explain this properly... So please accept I'm going to sound like a total idiot. In a carby(it's the original one from a crf50 if that help)... The needle should something hold it in place other then an e clip? Like when I look at it there is the slide(the big round piece that...

Found this pic in a post by nick AKA nickv1980 and thought it will help people who wonder about jetting and how it works and where different carb functions come into play.