This small board has eight rectifier diodes that will improve the waveform of the stepper motor, for in particular the older cheaper stepper drivers i.e. DRV8825 and A4988. Improving the waveform makes the motor less noisy, by reducing the vibrations. Because the vibrations are reduced the print quality also improves. Just put the board between your electronics and the stepper motor, orientation doesn't matter. For convenience, a small 4-way 20cm wire is included, tom hook up the board to your electronics.