Feature: 1.Every product has a unique Manufacturing Part Number label on the inner package that proves it has been qualified,which include Part Number,Model Number and inspection date information;2.If you have any questions about the item,please provide us the Manufacturing Part Number for checking,your profits will be guaranteed.3.A linear reciprocating motion is for a variety of mechanical systems, since the role of the support or drive, often with the support shaft, with the use of linear bearings.4.Good wear resistance and strength, high accuracy, hard to rust5.Linear bearing is widely applied to electronic equipment, food machinery, packaging machinery, medical machinery, printing machinery, textile machinery, machinery, equipment, robots.6.The Package include 4PCS Linear Ball Bearing,2PCS Linear Shaft Support and 1PCS Linear Shaft Optical Axis. Specification:Color:SilverWeight: 350gAccessories:4PCS SC8UU Model 8mm Inner Dia L34.5mm Linear Ball Bearing2PCS Aluminum 8mm Inside Dia 42x24x10mm Rod Rail Shaft Support 1PCS 8mm Outer Dia L300mm Cylinder Liner Linear Rail Shaft Optical Axis Package Include:1 Set of Linear Optical Axis Slide Block (7PCS)