My only problem at the (super writing) Lamy pens has always been to have to buy these super expensive Lamypatronen. As other fillers have but disappointed was my last resort, you transfer the ink from small low-cartridge with a syringe in the Lamy cartridges. With practice, though no more mess, but still: with this converter it is much more elegant. Just keep in an inkwell, raise, dab the edge and into the pen and the writing pleasure can begin. Ich finds super :-)