High quality materials and meticulous workmanship enable this upgrade kit's long service life. Perfect simple upgrade. Easy to install just switch the middle pins on the stepper motor harness that this kit come with. Perfect upgrades for your 3, 3 Pro, 3 V2 3D Printers. Absolutely Essential E3P mod: Your 3D printer accuracy can't be beat by anything else you've made before this. Made of high quality aluminium alloy, the timing belt tensioner can easily adjust the tension of belt. Minimal cost upgrade and maximum optimization. Low upgrade cost, Cost-effective(high cost performance), technical guidance, solution. Double Z structure runs smoothly. Using the T8 leads to 2MM screw. Use all-aluminum coupling and 42 stepper motor, stable operation. colour: black + silver Material: metal + plastic Package Contents: 1 Set x Dual Z-axis Upgrade Kit Only the above package content, other products are not included. Note: Light 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.