This is a repair sleeve if the tip of your fan speed knob on SG Forester broke and you don't want to pay $40 for a new one. I tried buying a used one on ebay and it came broken as well. The dimensions could use a little tweaking as it is a very tight fit. About 2 mins with a file and I was able to get mine to a nice friction fit on both ends. Printed with 0% infill, allows part to wedge onto the remains of your existing knob. You'll need to trim the inward most 7mm of your existing knob before fitting this sleeve. That's the part that snapped on the two I have.
Note: do not push too hard to get it fit onto the hvac module. the rotary switch inside is only held on with a split plastic nut. It will slip on its threads if you push too hard, forcing you to remove the whole module to reassemble.
I used the dims for the D-shaped interface with rotary switch from this model: https://www.thingiverse.com/thing:1776578/files
This model is pretty hacked together from tinkercad, and there are some random artifacts from that visible in the part. I may redesign this better but it works great for now and is not normally seen.
Photos: https://imgur.com/a/bEAReg8