the BIQU S42B closed loop stepper features a small OLED display and 4-button control panel to which one can set several stepper motor operating parameters such as stepper current, micro-stepping values, and others. Since the display and buttons are mounted at the rear of the motor, unless the motor is used "horizontally", visibility to the display and access to the push buttons is all but impossible. By using this PCB and associated PLA part, the display and 4 buttons are relocated to be accessable when the stepper motor is mounted vertically. Attached photos show a prototype build of the PCB but shows the general concept. More details can be found on thingivers post,