CNC Shield Board: Latest CNC Shield Version 3.0 for .GRBL 0.9 compatible. (Open source firmware that runs on an for that turns G-code commands into stepper signals).PWM Spindle and direction pins.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)Coolant enable,Uses removable A4988 or DRV8825 compatible stepper driversJumpers to set the -Stepping for the stepper drivers. (Some drivers like the DRV8825 can do up to 1/32 -stepping ).Compact design.Stepper Motors can be connected with 4 pin molex connectors or soldered in place.Runs on 12-36V DC. (At the moment only the DRV8825 drivers can handle up to 36V so please consider the operation voltage when powering the board.),Please note that this is an unassembled kit and Basic soldering skills are needed.A4988 Stepper Motor Driver Board is a breakout board for 's A4988 DMOS -stepping Driver with Translator and Overcurrent Protection; please read the A4988 datasheet carefully before using this product.Low RDS (On) Output,Automatic current decay mode detection / selection,Mix with slow current decay modes.Synchronous rectification for low power dissipation,Internal UVLO.Crossover-current protection,3.3 and 5 V compatible logic supply,Thermal shutdown circuitry,Ground fault protection,Load short-circuit protection,Five selectable step modes: full, 1/2, 1/4, 1/8 and 1/16.Colour: Photo ColorMaterial: PC+ metalWarning: Connecting or disconnecting a stepper motor while the driver is powered can destroy the driver. (More generally, rewiring anything while it is powered is asking for trouble).Note: Green or Red PCBPackage Includes:2 x CNC Shield Board8 x A4988 Stepper Motor Driver8 x Heat SinkOnly the above package content, other products are not included.Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.