BRAND NEW OLD STOCK ALL IN ORIGINAL PACKAGING I am selling my old stock of pen nibs, this listing is for nibs for a Isograph pen. These pens were used by designers like me back in the day to produce architectural drawings on tracing paper. Since then I use them for drawing lines that require a consistent thickness. They work equally well on paper and tracing paper. To use Rotring Isograph replacement nibs, you will need the correct Rotring Isograph pen holder. These nibs are not the same as Rapidograph nibs. If you want an Isograph nib please see my separate listing for nib sizes I have. Please make sure you are ordering the correct nib as I do not accept returns. If you need assistance deciding what you need please email me. Many thanks for looking.