Simple assembly: No welding, no modification, no need for other tools, easy to install. High quality: With all-aluminum coupling and original 42-34 stepper motor, the Double Z structure works smoothly. Solution: The double z upgrade kit is compatible with 3/ 3 Pro/ 3 V2/ 3D printers. The double Z upgrade kit is an excellent system that can provide you with a perfect solution to prevent the X rack from shaking. The kit contains the original 42 stepper motor, which can ensure stable operation and smooth movement, which greatly improves the accuracy of the 3D printer. Due to the updated dual Z, the X rises steadily and runs smoothly, which completely avoids the stacking of underlying consumables, reduces the layer pattern caused by the vibration of the Z, and greatly reduces the difficulty and frequency of leveling. Installation Notes: 1) Turn off the printer, unplug the power cord, and then use a hex wrench to remove the two screws that secure the power supply to remove the power