These Skinny-Mini converters were especially made for fountain pens that require an extra-thin body, such as the Kaweco Sport, the Visconti Van Gogh Mini Pen, and the Monteverde Tool pen. There may be other pens that require a thinner converter body. If you need a regular width mini converter, then take a look at our Mini converter. If you have any doubt, please refer to the below chart and measure your pen before purchasing a converter.