One Business Rollerball features an ultra-smooth, 0.6mm tip to give you an incredibly smooth writing experience. Innovative, Super-Flow system provides consistent ink flow from start to finish to make sure every drop is used. Large ink reservoir has a level indicator to prevent unexpected runout. Cap-off, waterproof ink does not run dry even if the cap is removed for two to three days & is suitable for documentary use. Rubberized grip zone provides a secure hold for relaxed writing. Cap has a sturdy metal clip & fits neatly on either end of the pen. Rollerball pen is produced with a carbon-neutral process.