This is a small finger wrench I designed to adjust the Disc Brakes on my Trek DS Tektro Novela Disc brakes.

As the pads wear I find that I need to adjust the stationary pad which requires a 5mm hex wrench. Because the spokes get in the way, trying to use a regular long handled 5mm hex wrench (or combination wrench) was a huge pain.

This design easily fits into the available space and allows you to quickly and precisely adjust the distance between the fixed brake pad (the one that does not move when you press your brake lever) and the rotor.

I made mine using PLA but ABS would work just as well. If you make one, especially for another bike/brake system or another purpose entirely I would appreciate a comment. I'm providing the FreeCad file so you can modify the shape/size as needed to fit your application.