Thias
Klein Fan
You can use them to tune your M900 or M73x derailleurs!
The main bolt is a direct fit. It is really nice and light. Titanium. (See picture above, XT bolz on the left, M951 to the right)
The bolt for clamping the cable also fits, as do the two little adjustment screws.
Even the cage might be swappable if you modify its bolt a little bit.
Anyone ever done this before?
I might stock up on inverse DRs from now on. They are usually dirt cheap!