I've just installed some powerful solar panels on the roof of my camper van and I needed something to create a ceiling passage to the saloon to protect the cables from friction and a visual impression leaves appealing way to hide the emptiness. I also wanted to prevent most of the debris from falling into the cabin as we roll down the road. After hours of searching the internet I found these oversized bushings. Nice clean looking white, matched the ceiling, easy to install, and all I had to do to make a hole big enough for two 4AWG wires was use an X-Acto knife to double the length of the pre-drilled hole. Hole. It was easy and I love the look.