That's interior insulated ductwork. You really don't want that - the interior insulation will get full of dust/dirt and probably mold (from condensation). You want externally insulated metal ductwork.

Why not ask?

I almost got my head chewed off for just touching it. Spoke to my contractor and got the answer from hvac person it’s not fiberglass. I am no expert but I think it is.

There's no reason for insulation inside duct and several reason it shouldn't. "SOME EQUIPMENT" such as air handlers and furnaces are manufactured with insulation inside to prevent damage during shipment.

" I almost got my head chewed off for just touching it. "

Who's working for whom on this project?

Thank you for the advice. I spoke to my contractor and told him I don’t want any inside insulation in my ductwork. Got some pushback saying that is how we do ductwork etc but then agreed to remove that one piece with inside insulation.

Two Types!