This is a custom-made adapter for Montblanc ballpoint pen refills. It's an adapter that allows you to use current refills in older MONTBLANC ballpoint pens (Noblesse and hammer trigger type). It was handmade with resin. I've confirmed that it fits without any problems. The third photo shows an example of how it's installed; the refill is not included. *The images are reused. Currently, it's difficult to obtain the genuine adapter. Would anyone looking for one be interested? Each item is carefully made, but please understand that it is a handmade product. *There may be tiny air bubbles.