This is an arm to use with IR sensor with Bondtech extruder and Revised X-Axis X-Carriage by Vekoj https://www.thingiverse.com/thing:3560116
Parts required:
M3*8mm screw
M3 square nut
Supports: No
Resolution: 0.2 mm
Infill: 20%
The author hasn't provided the model origin yet.