10pcs Thrust Ball Bearing Miniature High Precision Flat Steel Bearings Set (F4-9M 4x9x4mm) Features: 1. This ball thrust bearing set features high precision, high speed, and wear small. 2. Small frictional resistance, low power consumption, high mechanical efficiency. 3. High grade steel ball, quiet and smooth rotation at a high speed. 4. Small internal clearance and high machining precision. 5. Suitable for machinery manufacturing, equipment installation and maintenance.   Specification: Condition: Item Type: Thrust Bearing Bearing Material: Bearing Steel F2.5-6M: Inner Wheel Inner Diameter: Approx. Approx. 2.5mm / 0.1in Inner Wheel Outer Diameter: Approx. 6mm / 0.2in Outer Wheel Outer Diameter: Approx. 6mm / 0.2in Outer Wheel Inner Diameter: Approx. 2.7mm / 0.1in F3-8M: Inner Wheel Inner Diameter: Approx. 3mm / 0.1in Inner Wheel Outer Diameter: Approx. 3.5mm / 0.1in Outer Wheel Outer Diameter: Approx. 8mm / 0.3in Outer Wheel Inner Diameter: Approx. 3.2mm / 0.1in F4-9M: Inner Wheel Inner Diameter: Approx. 4mm / 0.2in Inner Wheel Outer Diameter: Approx. 8.8mm / 0.3in Outer Wheel Outer Diameter: Approx. 9mm / 0.4in Outer Wheel Inner Diameter: Approx. 4.2mm / 0.2in F4-10M: Inner Wheel Inner Diameter: Approx. 4mm / 0.2in Inner Wheel Outer Diameter: Approx. 9.8mm / 0.4in Outer Wheel Outer Diameter: Approx. 10mm / 0.4in Outer Wheel Inner Diameter: Approx. 4.2mm / 0.2in   Package List: 10 x Thrust Bearing   Note: 1. Please allow slight error due to manual measurement. Thanks for your understanding. 2. Monitors are not calibrated same, item color displayed in photos may be showing slightly different from the real object. Please take the real one as standard. cturing, equipment installation and maintenance.