Use this spacer to fill the gap between the short, but super nice, Jetstream SXR-80 series cartridges and the screw on Pen Type-A. This spacer is designed specifically for the SXR-80 series ink cartridges by Uni.
Feel free to download it and print it yourself.
Get some here. http://bit.ly/jetstreamcartridge
and ore info on Jetstream ink cartridges here. http://thewirecutter.com/reviews/the-best-pen.