I know that I can buy or print protective covers for the green part of the image on Index controllers but I haven't seen any way to protect the outer half-ring. Something that covers it completely would probably block the sensors so I was thinking about buying these small silicone/rubber bumpers and stick them all over the shell (red ciricles). Would this be a good idea or is there a better way? I don't have a habit of mashing my controllers against the wall but I want to have something just in case I have an accident.