Bearing ball set: Our bearing balls are installed between the inner race and the outer race to reduce friction when the bearing rotates and are the best tool for replacing the front and rear wheel bearings of your bike.Premium Material: Made of high quality carbon steel, with super high hardness and wear resistance, anti-rust surface, ensuring superior performance and long service life without the worry of daily scratches.Package includes: Includes 510 bearing balls, 13 of the most common sizes to meet most of your life's bearing needs, easy maintenance and comfortable life.Easy to store: Our bearing balls come in a transparent box marked with different sizes and quantities for each position for easy sorting and use, and you don't have to worry about mixing them up. Widely Used: Perfect for bicycle ball bearings, motorcycles, sliding screw, casters, household furniture, door locks, drawer slides, automotive industry and many other applications.