Stick Asymmetry Index clip (gamepadla.com)

A clip on the stick that allows you to limit its movement so that you can see how symmetrically it deviates using JoyT Progam (https://gamepadla.com/soft.pdl).
Video about: https://youtu.be/ZlqaoaxNvNg
More Info: https://www.reddit.com/r/Controller/comments/1dedai8/why_the_circularity_test_is_much_less_important/
You can buy ready-made printed braces here: https://ko-fi.com/s/fddaa72f22