Tornado Roller Ball Ink BLACK Refills by Retro 51 (REF5P-B) (Three Pack) Retro 51 Tornado Rollerball Ink Cartridge Refill (3-PACK) Color: BLACK (also available in Blue ~ Green & Red) Writing Nib: MEDIUM (also available in FINE & BROAD from Eclectic Collection) Retro 51 Model Number: REF5P-B for BLACK & REF57P-B for Blue Length: 3-7/8" in length