Features: 1.Complete electronics kit, used to build small CNC router, engraver, mill or robot. 2.GRBL 0.8 compatible. (Open source firmware that runs on an For that turns G?code commands into stepper signals). 3.PWM Spindle and direction pins,4?Axes support (X, Y, Z , A?Can duplicate X,Y,Z or do a full 4th axes with custom firmware using pins D12 and D13). 4.board, MCU: ATmega328, USB interface: ATmega16U2. 5.Suitable for Latest CNC Shield 3.0. specification: Suitable for Latest CNC Shield 3.0. board, MCU: ATmega328, USB interface: ATmega16U2. PWM Spindle and direction pins,4-Axes support (X, Y, Z , A-Can duplicate X,Y,Z or do a full 4th axes with custom firmware using pins D12 and D13). Complete electronics kit, used to build small CNC router, engraver, mill or robot. CNC shielding plate: the latest CNC shielding version 3.0 GRBL 0.9. Coolant Enable is compatible with A4988 or DRV8825 stepper drives running on 12-36V DC. Can drive four axes: four sockets for A4988, DRV8825 or other StepStick compatible drives. Compatible with GRBL firmware. : Condition: 100% Brand New Color: As Pictures Show Package List: 1 * CNC shielding plate 4 * DRV8825 stepper motor driver 4 * Radiator 1 * USB cable