3 Pack - Schmidt MegaLine 4889 Pressurized Refill - Black Ink SCHMIDT MegaLine pressurized technology enables not only a writing upside down but also in the most extreme environmental conditions as high speeds. Fits Fisher Space Pens, Diplomat Spacetec, first version Sensas and other ballpoint pens using Fisher Space Pen pressurized style refills. Refill Reads: SCHMIDT MegaLine 4889 M Length: 3 1/2 inch (89mm), Diameter - .189 (4.8mm) Made in Germany - Distributed by Lanier Pens - USA, Ensure TOP Quality product - buy direct from Distributor!