The Tubing (2) (except Ar/si/sw) is made up of components including this Vlv Assy,shot Air which is the most expensive.
The component with the lowest price in the TUBING (2) (EXCEPT AR/SI/SW) schematic is the Screw,tap.5x10.
In this schematic the "Clamp D 12.0 Tube" is used most often.