In this schematic the "Bolt-washer,6x28" is used most often.
Parts such as the F-4: Collar A,hndl Set, Bolt-washer,6x28, Holder B,under, Cap are included in the Nps50 Zoomer.dx 2011 (b) Japan Af58-190 F-4 parts fiche.
The F-4 is made up of components including this Post Comp,hndl which is the most expensive.
