Fountain Pen Parts Ink Converter Screw Type is a removable, small that enables fountain pen users for filling their pens with bottled ink instead of utilizing disposable ink cartridges. It is designed to be screwed into the back of the pen where the cartridge would normally go. It features a small piston mechanism, creating a vacuum for drawing ink into the converter if the user twists the back of the converter. The screw-type design guarantees a secure fit and avoids the ink from leaking out of the pen. The Fountain Pen Parts Ink Converter Screw Type can be conveniently removed and cleaned or replaced with another cartridge or converter, making it a versatile for fountain pen enthusiasts.