CNC Shield V3.0 features: Latest Arduino CNC Shield Version 3.0. GRBL 0.8c compatible.(Open source firmware that runs on an Arduino 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 Stepper drivers Uses removable Pololu A4988 compatible stepper drivers. Jumpers to set the Micro-Stepping for the stepper drivers. 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 Pololu DRV8825 drivers can handle up to 36V so please consider the operation voltage when powering the board.) Stepping Motor The most popular Nema 17 model with 1.8 deg. step angle (200 steps/revolution) 0.4A rated current/phase, allowing for a holding torque of 26Ncm(36.8oz.in) Connection:Black(A+), Green(A-), Red(B+), Blue(B-) Stepping Motor Specification: * Cable length: 11.8 inches * Phase Resistance: 30ohms * Inductance: 37mH+/-20%(1KHz) * Frame Size: 42 x 42mm * Body Length: 34mm * Shaft Diameter: 5mm * Front Shaft Length: 20mm * D-cut Length: 15mm * Number of Leads: 4 * Lead Length: 300mm * Weight: 230g Kit list: 1x CNC Shield V3.0 1x Keyestudio UNO R3 board 4x A4988 driver 1x USB cable 1x Nema 17 stepping motorCNC Shield V3.0 Features – Latest Version 3.0, GRBL 0.8c compatible, 4 Axis supported and 2 end stops for each axis.