Twsbi Fountain Pen Nib Diamond 580

TWSBI Diamond 580 replacement nibs are complete, swappable units including a steel nib and plastic feed, designed for easy, screw-in installation to change tip sizes (EF, F, M, B, 1.1mm Stub) or replace damaged nibs. They are compatible across the Diamond 530, 540, 580, AL, and ALR series