Simple Locking Shower Rings

I went to Target to buy some shower rings and they were sold out of the cheap plastic ones, so I bought some nice looking metal ones. Got home and they don't hold on well and are noisy to slide, so I made the cheap plastic ones on my printer and the problem is solved.

Simple split ring, one piece that when printed in a somewhat flexible material will be able to bend around the curtain rod and lock in place fairly snug.