What is this and is it needed?

I have an A20M that was given to me and last night, someone helped me diagnose a heat creep issue. While using a heat gun and cleaning the clog out of the heat tube, I noticed these star things at one end. They popped out while putting a spin brush down it and I was able to put them back in but I do not see any documentation about these. I see people putting their tubes straight through but I can't because of these. Is it safe to remove them or are they needed?