comments:
Check Amazon for these alternate Chinese made gel refills that have the same dimensions as the Writech ones. I have the Writech Space Up Astroline pens and a number of refills for various pens, so I checked to be sure. The Uniball, Zebra, Pentel, and their copycats are too wide and will not fit into the front end of the pen which is made to fit the Writech refill with no wiggle room. I have some generic Chinese refills that DO have the same dimensions as the Writech ones in length (110mm) and width (5.5mm) and they will fit. It doesn't matter what "brand" they are listed under as long as they have these dimensions. Here is a listing on Amazon US that shows you what I'm talking about and shows the measurements in the photos and the text description: https://www.amazon.com/Pcs-Retractable-Black-Refills-Point/dp/B0D2DP4CBN?th=1