NightWriter Refill Kit - Fits The Pilot's Pen, NightWriter LED Pen, same as Cross 8518-4 refills (black ink) BLACK Ink refill for The Pilot's Pen "NightWriter", unique LED Powered Pen Includes three (3) refills; Same size & quality as Cross 8518-4 refills Easy to replace by unscrewing the pen top removing the old ink cartridge & inserting the replacement ink Economical replacement cartridges extend the usefullness of your Pen Same size and quality as Cross 8518-4 refills