Schmidt K6 Threaded Universal Fountain Pen Ink Converter - Pack of 2 Schmidt K6 Premium Threaded Universal Fountain Pen Ink Converter. Schmidt K6 is the premium universal ink converter on the market. This will fit a wide range of Pens that will take standard ink converters. Schmidt K6 is a threaded, screw-in converter. The additional threaded screw section allows the converter to be screwed into the front of the pen so as not to come loose. Famous high quality german standard Schmidt K6 universal fountain pen ink converter is design to world. German design and function, High quality german design Schmidt K6 ink converter, Threaded section ensures a tight fit and secures to your pen, Made from the highest quality parts, Type: Converter, Body Material: Plastic Fitting: Screw-in, Ink Viewing Window: Transparent, Filling Mechanism: Piston filling, Compatiblity: Compatible with most pens that fit standard international long cartridges, Pack of 2 Piston converter for plug-in assembly with two metal bands, nickel-plated crystal clear ink reservoir with elastic sealing.