CNC Shield Board: Latest CNC Shield Version 3.0 for arduino. GRBL 0.9 compatible. 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. Compatible with A4988 or DRV8825 stepper driver. Runs on 12-36V DC. DRV8825 Stepper Motor Driver: Stepper motor driver (upgraded from A4988, 2.5 A max current/phase. It s not arduino official board but it s compatible with all arduino software and hardware). Nema 17 Stepper motor Specification: Model No.:17HD48002H-22B Step Angle: 1.8 deg Holding Torque: 59Ncm(84 oz.in) Rated Current/phase: 1.7A Frame Size: 41 x 41mm Body Length: 47mm Shaft Diameter: 5mm Shaft Length: 22mm Weight: 380g Mechanical Endstop Connection Description: Red line connect VCC (ramps of +) black wire connect the GND (ramps of -) Green Line connect SIGNAL (ramps in s) Tips: Under normal circumstances, the system must be configured to at least three mechanical switches. Advantage: Easy to install, the more common used styles. Length of Cable: 70 cm Great Package Includes: 1 x CNC Shield Board 1 x Longruner UNO R3 Board 1 x 1.5m USB cable for R3 Board 3 x Nema 17 stepper motor 1.7 A (with bracket and screw) 3 x Nema 17 Stepper Motor Mounting Bracket 3 x Mechanical Switch Endstop 3 x 3Pin 70cm Cable 4 x DRV8825 Stepper Motor Driver 4 x Aluminum heatsink w/ 3M tape backing 12x M3 Screws for bracket of stepper motor