If you need a replacement nib for your technical drawing pen, we should have it here, and any we don’t, we can probably get.
Drawing pen nibs (or technical pen nibs) come in a variety of different sizes, from as low as 0.13mm up to 2mm, it all depends on the width of line you need for the project. They are often colour coded depending on the size, so that they can be quickly identified and swapped.