[Best Upgrade]The dual z axis upgrade kit is compatible with 3/ 3 Pro/ 3 V2/ 3D printer.Easily improve 3D printers with low cost efficiency to Dual Z axis mode. [Smooth Running]Upgrade Single Z-axis structure to a dual Z-axis structure, will make the printer more easy to Leveling, both ends of the X axis are raised and lowered synchronously, which reduces difficulty and frequency of bed leveling obviously. [Increased Accuracy]Dual Z Axis structure reduces the layer ripple caused by Z-axis vibration, avoiding backlog of filament thoroughly, which improves stability of 3D printing and increases the printing performance of 3D printer. [Stable Performance]Compared with Closed Timing Belt, this 3D printer parts set still retains the design of stepper motor to screw rod smooth operation. [Easy Assemble] - No need to modify or weld the machine, no need to replace motherboard, this 3D printer accessories kit comes with instructions, could be assemble quickly. for 3/ 3 V2/ 3 Pro. Colour:black Material:Metal Package Contents: 1 x Z-axis double screw accessories set Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.