1、APPLICABLE MODEL: Upgrade Y axes linear slide rail kit, suitable for Neptune 3, for Neptune Pro, for Neptune 4, for Ender 3, for Ender 3 Pro V2, for Ender 3 S1, for Ender 3 S1 Pro. 2、STABLE OPERATION: This linear guide rail has high rigidity and stability, ensuring excellent accuracy during movement, reducing printing vibration, and improving printing quality. 3、HIGH EFFICIENCY: This linear motion slide rail has good smoothness and low friction, reducing energy loss and mechanical wear, allowing 3D printer to work at higher speed. 4、EXCELLENT STEEL: This 3D printer rail is made of high carbon chromium steel, which has strong wear resistance, high hardness, stable movement, low noise, and uniform force. 5、INCLUDED PARTS: Including 2pcs rails, 6 sliding blocks, a pack screws, and other accessories, this 3D printer rail kit is easy to install and use, greatly improving printing efficiency.