CNC Shield V3.0 Expansion Board R3 Board 4*A4988 Driver 4*4401 Stepper Motor Kit with Heatsink USB Cable for 3D Printer

Latest CNC Shield Version 3.0. GRBL 0.8c compatible. (Open source firmware that runs on an R3 board that turns G-code commands into stepper signals) 4-Axis support. (X, Y, Z , A-Can duplicate X,Y,Z or do a full 4th axis with custom firmware using pins D12 and D13) 2 x End stops for each axis (6 in total); Spindle enable and direction; Coolant enable.