Latest CNC Shield Version 3.0 GRBL 0.8c compatible. (Open source firmware that runs on an for 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 Uses removable A4988 compatible stepper drivers. (A4988, DRV8825 and others) to set the -Stepping for the stepper drivers. (Some drivers like the DRV8825 can do up to 1/32 -stepping ) 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.) Colour:Photo Color Material:plastic+metal Package Contents: 1 x CNC Shield V3.0 1 x for UNOR3 Board 4 x A4988 Driver 4 x 4401 Stepper Motor 1 x USB Cable Only the above package content, other products are not included. Note: Light reflection 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.