HIGH QUALITY: Made of high quality metal, durable with the resistance of wear and collision. FEATURE: It is characterized by small frictional resistance and high rotational speed and can be used on mechanical parts that are subjected to loads or axial loads, such as machine tool, electronic equipment, . GOOD DESIGN: Exquisite design, two sides metal sealed ball , with good dustproof effect. Built-in precise Mini provides running and long service life. APPLICATION: Standardization size, used for machine tool, electronic equipment, pump industry, plastic machine, motor and more. size:15x28x7mm :metal colour:Black + Silver Package Contents: 10 x Bicycle hub Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.