SU Space Pen Refills - for Multifunction Pens, Mini Pens and Data Pens
The SU Space Pen Refill fits the Fisher Q4 and most Multifunction pens, Data pens and mini ballpoint pens. The SU refills have two break off points to adjust the size to fit a wide range of pens. Simply hold your current refill against the Fisher SU refill and snap it off at the correct length. The first break off point is at 67mm which suits Most Multifunction and Data pens. This refill was originally developed by Paul Fisher in 1953 when ballpoint pens were new and every pen took a different refill. Fisher's unique break off points allowed this refill to fit a wide range of 1950s ballpoint pens. These days the first break off point is the most common size but there are still quite a few pens that take the longer sizes.