Features:1. The latest CH340G CNC Shielding Expansion Card version 3.0.2. Adopt board MCU, USB interface. With 30cm USB cable.3. With 4 DRV8825 stepper motor drivers with heat sink.4. 3 pieces of stepper motor for NEMA-17, 84oz (59 cowhide) 47 mm body 1.8 degree with mounting bracket kit. 3D printer CNC robot with 3 mounting brackets and 12 M3 screws.5. 3 mechanical limit switches for Endstop for 3D printer for RAMst 1.4 with 3-pin 70 cm cable.Specifications:for CNC guarding board:The latest CH340G 3.0 versionCompatible with: for GRBL 0.9For the 4 axes (X, Y, Z, A-Can copy X, Y, Z or use the custom firmware with pins D12 and D13 to make the complete 4th axis)2 * end stops per axis (6 in total)Coolant releaseCompatible: for A4988 or DRV8825 stepper drivePower: 12-36V DCFor DRV8825 Stepper Motor Driver: 2.5 A Maximum Current / Phase, Suitable for Software and HardwareFor Nema 17 stepper motor:Model: 17HD48002H-22BStep angle: 1.8Holding torsion: 59Ncm (84 oz.in)Rated current / phase: 1.7AFrame size: 41 * 41mm/1.61*1.61inBody length: 47mm/1.85inShaft diameter: 5mm/0.2inShaft length: 22mm/0.87inMechanical limit stop connection instructions:Red line connected to VCC (slope +)Black line connected to GND (slope - )Green line connects SIGNAL (slope in s)Tips: Under normal circumstances, the system must have at least three machinesSwitch to the configuration you want.Advantages: easy to install, the most common styleCable length: 70 cm/27.56inPackage List:1 * CNC guarding board1 * board4 * Stepper motor driver for DRV88254 * Aluminum cooler with 3meters tape3 * 1.7 A stepper motor for Nema 173 * Stepper motor mount for Nema 1712 * M3 screw, bracket for stepper motor3 * mechanical switch end3 * 3pin 70 cm cable1 * 30cm USB cable for board3 * shock absorberNote:Please note that the new type and old type of this product will be sent randomly, and make sure you will not mind before ordering..