Cross RollerBall Pen Medium Black Gel Selectip Refill - 8523This official Cross slim gel rolling ball refill in Black, medium nib is a smooth alternative to the free flowing ink of a fountain pen, with the convenience of a ballpoint pen. Rollerball Refill Slim Black Gel. Compatible with Click Design Style Cross refills are created with the finest quality inks. An ink refill that is suitable for everyday writing. Classic ink colors are reliable for use on all paper types Nib Technology Slim gel rollerball pen