[HIGH QUALITY]Made of steel, well construction, high hardness, strong and durable, no deformation. Corrosion resistance and high hardness, they could for a long time, surface is round and , no residual burr, free of cracks and chips. [WIDE APPLICATION]Steel ball is widely used in motorcycles, bicycles, casters, household furniture, door locks, drawer slides and many other applications. [PRODUCT FUNCTION]Bearing balls are installed between the inner ring and the outer ring to reduce friction when the bearing rotates. Will reduce the damage to the machine and extend the service life. [HANDY PACKING]Total 15sizes 580pcs steel ball assorment kit packed in a clear plastic case, makes it easy to find correct item quickly, saves your time of running around looking for a particular size ball. SPECIFICATIONS: 1mm=50pcs 1.5mm=50pcs 2.0mm=50pcs 2.5mm=50pcs 3mm=50pcs 3.5mm=50pcs 4mm=50pcs 4.5mm=50pcs 5mm=50pcs 5.5mm=30pcs 6mm=30pcs 7mm=20pcs 8mm=20pcs 9mm=15pcs 10mm=15pcs Note: due to different production batches, the plastic box style is random, ' accept the specified Colour:silver Material:steel Package Contents: 580 x Stainless Steel Precision Steel Balls Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.