Upgrade T8 Anti Backlash Nut: Made of high quality brass material,not oxidized and corrosion resistant. anti-backlash mechanism and add stability and smoother functionality to help solve backlash issues on your 3D printer. Lead Screw Top Mount: Made of premium aluminum alloy,it helps to keep the z-axis much more stable to minimize deviation while printing, and it minimizes the need to relevel the plate between prints. Wide Compatibility: Work well with CR10,-10S,-3 , 3S,Ender3 Pro and 3D Printer and other 3D printer which lead screw fixing holes is and two holes distance 18mm. Great accessories Kit for 3d printer, more stable and convenient while in a print job. Colour: As shown Material: metal Package Contents: 1 * T8 anti backlash nuts 1 * lead screw top mount 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.