The Kaweco MINI Converter can be used instead of replaceable ink cartridges and allows to fill up ink directly from an ink bottle. Thanks to the clever folding mechanism of the piston rod, the converter can be reduced in size by almost 20% while holding the same ink capacity. The converter fits the following Kaweco fountain pen series: AL Sport, Brass Sport, Skyline Sport, Classic Sport, Frosted Sport, Liliput.