The component with the lowest price in the AIR CLEANER (FES1257/A7)(FES1507/A7) schematic is the Screw Tapping5x25.
A sample from the products for the Air Cleaner (fes1257/a7)(fes1507/a7) include: Tube,a/i, Plug,brthr,tube, Screw,tapping 5x6, Tube,drain.
On this parts fiche the Screw Tapping5x25 is the most specified component.