Feature: 1. High Speed Operation: High speed operation, rotating with minimal friction resistance, so as to obtain high accuracy and stable motion 2. Exquisite Production: Using advanced technology, the bearing surface is glazed and flat, waterproof and dust prevention, not easy to rust, and long service life 3. High Carbon Chromium Bearing Steel: Steel material, high hardness, good wear resistance and contact fatigue strength, the core maintains good toughness, and can carry high impact loads 4. Mute Effect: Well made, working in coordination with the machine, greatly improving the operating efficiency of the machine, and bearing noise is smaller 5. Application: Widely used for gearboxes, instrumentation, motors, household appliances, internal combustion engines, transportation vehicles, agricultural machinery, construction machinery, construction machinery, roller skates, yo yo, etc. Specification: Item Type: Self Aligning Ball Bearings Material: High Carbon Chromium Bearing Steel Uses: Widely used for gearboxes, instrumentation, motors, household appliances, internal combustion engines, transportation vehicles, agricultural machinery, construction machinery, engineering machinery, roller skates, yo yos, etc. Parameter Specifications: Model Inner Diameter, Outer Diameter, Thickness(Approx.) 1200 10mm / 0.40in, 30mm / 1.18in, 9mm / 0.35in 1201 12mm / 0.47in, 32mm / 1.26in, 10mm / 0.40in 1202 15mm / 0.59in, 35mm / 1.38in, 11mm / 0.43in 1203 17mm / 0.67in, 40mm / 1.57in, 12mm / 0.47in . Package List: 10 x Bearing Note: Please pay attention to match the corresponding size before use