Wouldn't have thought about rubber o-rings.... interesting option.... Thanks!First of all, Mars C-rings is not the same as industrial
Industrial rings can be installed and removed with special tool for that and can be reused several times
Mars C-rings
You have to expand or squeeze these to fit
View attachment 907189
Industrial C-rings
Comes in a lot of different shapes
You can use a special tool to remove or install it
View attachment 907200
If you have just one Mars and like to change lenses back and forth you can use rubber o-ring like these
but have to pick a tight one/ diameter. (this is industrial not the ring's you're thinking about)
View attachment 907201