Insulation mat ??

I was ordering some exhaust pieces from the Max6X6 site when I came across 8"x8" insulation mat for MaxII. I did not find anything like this on my MaxII when I disassembled it. The only parts manuals I find are for machines a bit earlier than mine. Any idea where this mat is used, or if I need it?

It goes under the heat shield inside the body

Thank you very much!