Furnace filter for Carrier model 58DHB055-CC
 

I'm trying to find air filters for a Carrier model 58DHB055-CC. Evidently
there are supposed to be two filters that sit in the return-air plenum above
the blower in a V configuration. Is there a part number for this filter?
Perhaps a larger filter that can be cut down to size? I haven't been able to
find any information about this furnace on the internet. I don't even know
how old this furnace is. Presently, the furnace is running without any
filters at all. (Is this a terribly bad thing to do?).

--
Bob D.