This plunger is specially designed for the 'O' & 'N' type leakproof Onoto and has been produced using original specifications.
Due to the unique design of this plunger NO separate backing washer is required which improves the design and gives a better seal
It is attached to the rod by a 5ba left hand thread and is black in colour. The main body and the end part are assembled using the same 5ba L/H thread which ensures a good seal with the rubber washer
Each plunger purchased comes complete assembled with a 7.78mm diameter rubber washer and is held together with a 0.8mm diameter pin