If you're asking about those specific C4D's I used they don't really have names and I couldn't honestly tell you where I got them, sorry. If you're asking what a C4D is in general; like I said, it's a rendered shape that you can use in signature making, usually by blending it into a background as I did in the tutorial. If you need more specific info a Google search on 'C4D' should explain it better than I ever could. Good luck with you sig attempt!