Kat, ARB air setup.

Ok so I was wrong about the little hole. two little holes are for the air lockers and the big one is for the pressure cutoff switch. If you use a "T" on the big hole you can have a quick connector for an air hose and the cutoff switch.

Thanks. You told me the big one the first time so you weren't wrong. Are the connections for the two solenoids the same size on yours? They look like they are but the two smaller holes on mine are different sizes. Where can I get the "T" - Pep Boys or something?

you could go to home depot for a fitting. Mine may have come with the ARB air line kit. I'll have to check on that.