1、COMPATIBLE MACHINES: The CNC shield expansion board driver is a flexible package with a three axes stepper motor driver that is compatible with most shield designed for microdrive laser engraving machines and three axes CNC engraving machines 2、VOLTAGE AND MAINTENANCE: The CNC shield expansion board driver kit uses a power supply DC5V interface and 7.5‑12V voltage input, which is compatible with for GRBL for easy maintenance, parts replacement, upgrades and expansion 3、CONTROLLABLE MOTOR: The 2A CNC shield board driver can be controlled within a two phase, four wire stepper motor and can be started simply by connecting to the computer using a USB cable or using an AC to DC adapter or battery 4、A4988 DRIVE: Easy stepping and direction control can be made before making the A4988 module prevent static in short circuit 5、MAIN PURPOSE: CNC shield board driver can be used for engraver or 3D printer driver to build small CNC routers, engravers, milling machines or robots