1PC 6mm OD Linear Shaft Length 1000mm Cylinder Liner Rail for 3D Printer Axis CNC Parts Model: Optical Axis OD 6MM Length : 1000mm Color : Silver Quantity : 1pcs Feature: Thick enough and the surface is smooth Durable for using and easy to install. The optical axis is widespread used in automatic driver. Usage: Linear axis in the automatic rotation device has widely used, such as industrial robots, automatic recording instruments,computers,precision printers,special gas tank,automatic wood machines and other industrial machines.And because of its hardness, can extend the life of an ordinary instrument. Note: Please note that the package included only one linear optional axis.