Kaweco Skyline Sport Calligraphy Nib Unit - BlackAbout Kaweco Skyline Sport Calligraphy Nib Unit Black If your Kaweco nib is beginning to wear or you just fancy a change of stroke width, these spare front sections with polished steel nibs simply screw in to your existing pen! Available in Black or White to suit Skyline Sport models and in nib sizes 1. 1, 1. 5, 1. 9, 2. 3 and Twin. View the Kaweco Pens range.