Inkvo Universal Twin Spool Typewriter Ribbon - Combo Pack - Red and Black Ink - Fresh Ink Replacement - Compatible with Smith Corona, Royal, Remmington, Underwood, Brother, Olivetti, Olympia and MoreSuperior Quality: We spend more on our ribbons than any competitors in order to provide superior quality to our customers. That includes fresher and more saturated ink, with more vivid colors.Longer Lasting: Our ribbon length is double many of our competitors! Fresh ink that is recently made makes all the difference! We have a strict freshness policy for all Inkvo products. Many competitors will store ribbons for years!Technical InformationCompatible Models: A list of confirmed compatible models is available in the image gallery. If your model is not listed, it is still possible that our replacement will work with your machine. In the event that it does not fit, you can always re-spool our ribbon on to your old spools!Commonly used models include: Many Adler, Brother, Corona, Hermes, Olivetti, Olympia, Royal, Royalite, Remmington, Sears, Silver Reed, Smith Corona, Swintec, Underwood and more!Spool Diameter: The diameter of the spool is 2 inches or 5 centimeters. This is the most universal typewriter ribbon spool sizes!Hole Sizes: The outer hole sizes are 3 millimeters in diameter and the inner hole is 5.5 millimeters in diameter.Ribbon Width: The ink ribbon width is 1/2 inch or 1.27 centimetersRibbon Length: 10 meters or 32.8 feetWhat's Included: 1 Pack of our Inkvo Universal Twin Spool Typewriter Ribbon with Red and Black Ink