This is a replacement adjustment bolt for the bowden cable that sets the shift points for the automatic transmission in the mercedes benz 300T/C/D w123 models with the OM617 engine. The slot in the side is so it can be installed without disassembling the entire bowden cable itself. Ideally it should be made of metal or printed with ABS but I used PETG with 100% infill. Threaded portion is M8x1.25.
The author marked this model as their own original creation.