You can print just the cable magnet as it will stick to anything magnetic. The magnets I'm using are 6x2mm neodymium magnets.

I've also made a blank magnet base for you to add to any existing model/mount or design your own around it.

The other two files are magnet bases I use myself - they won't fit every use case but they're there in case they do!

Most important thing: Make sure your magnets are always in the same polarity on the cable vs the base - You want them all to attach easily.