The Basic and the Loom accept the Faber-Castell Design converter item #148785. If for the Loom, you find that this converter is not fitting into the pen you have there, it is due to a slight design change that took place some time ago. You have an older style that will need to be returned for conversion in order to accept the converter. Please see our Repair Services section for return details.
The pens will not allow all converters by other companies. We suggest using the Design Fountain Pen Converter only.