I bought an idle control valve off of ebay and it came with a metal spacer that has 2 what look to be set screws in it and a little glass lens. I left it off since there wasn't one on there when i took the old one off and i didn't want to put something on my car that i didn't know what it was for or how to adjust it. Any help with findong out what this is and how to use it would be great.