PenBBS 355 (Blue)
This pen features a high volume ink tank with a piston arrangement ‘copied’ from the Conid ‘Bulk Filler’ system. With most piston fillers, the piston cannot retract to the end of the pen because of the differential screw mechanism behind it. In this pen, the piston is operated by a rod which unscrews from the piston after filling, allowing the piston to stow at the back of the pen, while the rod is drawn back into the body. In this way, a huge volume of ink can be stored.