A lot of USB cables have accumulated, and some of them are only for charging, without data transfer. I decided to mark them with a colored ring so that I could immediately take the right one.

I use this tester to quickly check the cables: 

https://www.ozon.ru/product/tester-usb-kabeley-s-akrilovym-korpusom-1851156296/?tab=reviews

The attachment contains 6 files for different cable diameters. The numbers in the file name correspond to the outer diameter of the ring - from 5 to 7.5 mm. In order to put on the ring, you need to spread its ends along the Z axis (like a Grover washer).
PLA printing with 100% filling.