The Madison Fountain Pen is the only pen model within Osprey pen offerings that is available with a Size 6 Ultra-flex Steel nib. The nib is friction-fit with an ebonite feed, directly into the outer section of the pen. This outer section does not have internal threads and hence cannot accept any interchangeable nibs.
In order to use the entire range of Osprey nib unit offerings, namely #6 Steel, #6 Gold, Special Grind Nibs, #5.5 Ultra-flex, Zebra G and Phosbronze flex, you need a second section called the Madison2 Section that has internal threads to fit the interchangeable nib units. Make sure to order Madison2 Section if you don't already have one.
Madison model comes in 2 colors: Midnight Blue and Nimbus.
You have several options to shop from:
1) Bundle & Save - This allows you to buy multiple nib units at a discounted rate
2) Single Nib Options - If you wish to choose a single nib from the #6 Steel, Ultraflex series, Zebra G or Phosbronze offerings, you would select from this option.
3) Madison Zebra G Fountain pen - If you already know you want a Zebra G, you can directly go to this link and make your selection.
4) Madison with Special grinds: If you wish to choose a single nib from the variety of economical special grinds that we offer, you could select from this option.