The original knobs on the radio all split down the middle, so after trying unsuccessfully to find more in various junkyards, I decided to design new ones and print them. After they were done, I put some white paint I had laying around and brushed some into the recessed line to see where it was pointing better. Each one only takes around 4 minutes to print on a slower speed, use high resolution, infill doesn't really matter. It uses the original tension clips that go on the knob post, so make sure you take them out of the original knobs or off of the post before trying to put them on.