If I look at the silver piece of metal that sticks out, it looks like there is some brown coloring to it, and the bar grinds on it when moving, causing rough adjusting

That works as it is intended to do so.

Might also help vibrations as

I was stoked to finally get away from a standard mic stand; and it worked exactly as I'd hoped for the first several weeks with a Behringer C-1.

Works as it should and has a great reach over my cluttered desk!

This arm works as it is supposed to and is a must have for adding a mic to your computer setup

PL-2T Boom Arm, you won't be disappointed.