Rear Derailleur Adjuster Knob

The plastic knob for the barrel adjuster on Shimano 105 and GRX400 rear derailleurs.

I have both derailleurs and have tested the part on them. Unfortunately, I haven't found any other derailleur model that uses this identical adjuster knob.

Use the original orientation if you have confidence in your printer's calibration. If you prefer a more reliable print, rotate the model 180 degrees (so the knob top faces the build plate) and enable support structures. The model is optimized for standard printing profiles: 0.2mm layer height with a 0.4mm diameter nozzle.