When I was working on the generator on our Sunstar, I noticed that there was no bushing or grommet protecting the battery and control cables from chafing on a hole in the surrounding enclosure.
Actually, there was a half inch piece of what must have been the original grommet holding up the red cable.
That's a 1 3/4" hole, so I got a suitable 1 3/4" nylon bushing. The more correct way to install it would have been to disconnect the cables and install the bushing. However, being ambitiously lazy, I snipped through the bushing with some dikes and snapped it around the cable and then into the hole.
I could have gotten another rubber grommet, but since the last one seems to have rotted away, I went with the nylon.