Naturally Aspirated Air Compressor

[kozakvod]

I was doing some looking on QS for a code I had and I noticed this on the Service page.

Naturally Aspirated Air Compressor Upfit for Kenworth and Peterbilt

Can someone please explain what this is? Showing my ignorance I know, but then there's a lot of things that fall into that category for me, so no shame in my shame.

I looked at the kit parts and it some how pipes across the engine back into the fresh air side of the turbo, i guess/think?