Some items from this specific schematic: Filter,sub Air Cl, Tube,5.5x120 (w22, Valve Comp.,air J, Cover,sub Air Cle.
This Valve Comp.,air J is the most expensive of the items that make up this Solenoid Valve/ Sub Air Cleaner (3) assembly.
On this parts fiche the Suspension Sol Vl is the most specified component.