Spare aluminium finish nibs to fit the TWSBI Diamond 580 fountain pen, fitted with the most popular fine nib as standard. For those that prefer a wider line weight we have three additional options for you: * Medium * Broad * Stub 1.1mm The nib units can be easily swapped into your 580 fountain pen. As a guide, for standard handwriting we'd recommend a fine nib. For larger handwriting, choose a medium nib. For statement or extra large handwriting go for a broad nib. Stub nibs are untipped and are used for italic writing, so are perfect for signing cards, invitations and creating larger work.