Ghost Ring Rear Sight for Diana Charger

The Diana Charger air pistol/rifle has very nice blade sights, but after playing around with the ghost rings on a .22, I wanted the same rear sight. The ghost ring works well with my aging eyes. The center of the hole is 13.5mm above the “deck” and works well with the factory front post.  It's a 4mm hole, 6mm outer diameter. 

Printing with 4 vertical layers and 15% infill works nicely in PLA and PETG-CF, it's a snug press on fit. The Freecad file is included if you want to adjust the height or anything else.