These adapters require MGN12H rails for the Ender-3 pro and Ender-3 V2, and MGN9H rails for the Ender-3. the length required is 300MM (we also have the CR-10 version,too). This kit allows you to add linear rails to your Ender3 series 3D printer's Y-axis, replacing the V-slot roller wheels moving system. They are only with MGN12H rails for the Ender-3 pro and Ender3 v2, and MGN9H rails for Ender-3(adapter is different,too). We offer MGN12H/MGN9H linear rail kit in high quality black color or Hiwin Original in 300mm
