OPUS 88 Replacement #250 BOCK Nib Unit (for FLORA model)Swap your nib. Change your writing. This is the replacement nib unit for the Opus 88 pen models that are fitted with a Bock nib unit (includes Flora). It does not fit Opus 88 models that use JoWo housings, such as the Omar, Demonstrator, Harmony and Jazz. Who this is for You love your Opus 88, but want a different line width Your nib is damaged, scratchy, or inconsistent You want to experiment with line width without buying a new pen You're a nib