Features:Latest CNC Shield Version 3.0.GRBL 0.8c compatible. (Open source firmware that runs on an UNO 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 Pololu A4988 compatible stepper drivers. (A4988, DRV8825 and others)Jumpers to set the Micro-Stepping for the stepper drivers. (Some drivers like the DRV8825 can do up to 1/32 micro-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 Pololu DRV8825 drivers can handle up to 36V so please consider the operation voltage when powering the board.)