Diopters can be a pain so why not mount your entire set into holders with cinelocks. Change splits without moving the edge or quickly put into position

- Snap fit

- Specialty split holders prevent seeing retainer ring if you just want to tickle the edge of frame.

- Reverse split holder for hiding the edge in a rounded object

- Helicoil metal threads

- Standard 138 is roughly optical centered if you use a cinelock on a lens support to rod mount