12 size precision steel balls assortment kit contains: 90 pcs 1mm, 80 pcs 2mm, 80 pcs 2.5mm, 50 pcs 3mm, 50 pcs 3.5mm, 50 pcs 4mm, 50 pcs 4.5mm, 50 pcs 5mm, 30 pcs 5.5mm, 30 pcs 6mm, 20 pcs 7mm, 20 pcs 8mm. Made of 304 stainless steel. Uniform size, high wear resistance, high precision, smooth surface, no burr, excellent appearance. Widely used in auto parts, motorcycles, bicycles bearings, casters, drawer slides, etc. Can also be used as mixing balls for stirring paint, nail polish, and similar applications. The surface is coated with a small amount of grease to reduce friction during bearing operation and to prevent corrosion and rust, helping to reduce machine wear and extend service life. Packaged in a storage box. Steel balls are sorted by size and stored in separate compartments for easy identification and organization. Note: Due to different production batches, the style of the plastic box may vary. Color: Silver Material: Stainless steel Dimensions: 10.01 x 3.99 x 1.30 cm Package Contents: 600 x 12 Size Stainless Steel Precision Steel Balls Note: The package includes only the items listed above. Other products are not included. Note: Lighting effects and monitor settings may cause slight variations in color between the image and the actual item. Measurement error allowed is +/- 1-3 cm.