This a CNC shield V4 that properly work with Arduino Nano board. It can be used as driver expansion board for engraving machines and 3D printers. It has in total 3 channel slots for A4988 or DRV8825 stepper motor driver modules for driving 3 channel of stepper motors. Each channel of stepper motor only needs 2 IO ports, which means 6 IO ports is sufficient to manage 3 stepper motors. This shield can make quick work for managing stepper motors in your project.