Hi Dutchie one... Those are skin files. One of them looks like a broken glass for a gauge? Anyhow they should be placed in your Texture/TNormal/tex folder if your using them.
What exactly they are number one? I don't know.
But if you want to see what these files look like you can use a free program called Art of Illusion found here,
http://aoi.sourceforge.net/
I hope that helps...
