This listing is for the Jowo-compatible Osprey second generation Size 6 Ultra-flex 2-Tone Nib units with ebonite feed.

The improved design boasts of a custom ebonite feed with tail, and a threaded housing, giving many folks the advantage of writing with ultra-flex nibs using either a pre-filled ink cartridge or with bottled ink using any generic international converter.

Typically, most suppliers in the market place sell Ultra-flex nib units with a plastic feed. We are one of the handful of folks that give an ebonite feed  with an ultra-flex nib. An ebonite feed keeps up with the ink demands of a flex nib, unlike a plastic feed.

 Do not use India Inks, they can clog the ebonite feeds. Fountain Pen inks are recommended. Few examples of inks that work best with Osprey Zebra G or Stainless steel  ultra-flex or the Titanium ultra-flex are :  The Noodlers standard Black , Platinum carbon Black, D’Artremis document Black ink, Pilot Iroshizuku line of inks, Rohrer & Klingner SketchINK., etc.

Size 6 Ultraflex nibs are also available in Steel: