18k nib unit size 8. Ebonite feeder and ABS housing.
Size 8, that means that the feeder is 8 millimeters in diameter. Thread housing M9.4x0.5, a drawing with dimensions can be found in the las picture of the gallery in this product.
Customized breather holes are hand cut.
We do offer a tip regrinding service for your selected nib. To know more about them click here.