I suspect there are better models available, but I really enjoy the design process so I almost always design my own accessories. This model requires two M4x35mm bolts and nuts. I use an old soldering iron to secure the plugs.
The knobs are an early, but acceptable to me, attempt at knurling.
I hope it works as well for you as it does for me. I'm planning on another model that will allow easier rotation (this model requires removing the bolt to change the indicator's orientation).
Thanks for looking.
The author marked this model as their own original creation.