Description: Four different specifications allow you to choose the most suitable one according to your needs. Simple and convenient operation steps will not waste your time and energy. Wear resistance and high hardness allow it to be used for a long time. Professional and exquisite workmanship makes it very sturdy and durable. Made of steel material, it is very durable to use. There are four specifications for you to choose from: 2cm, 2.5cm, 3cm, 4cm. It is suitable for folding bike, road bike, mountain bike, bicycle and so on. Item Name: Front Fork Headset Ball Material: Steel Front Hub Ball Holder: 7 Steel Balls Rear Hub Ball Holder: 7 Steel Balls Center Axis Ball Bracket: 9 Steel Balls Rear Hub Ball Holder: 20 Steel Balls Features: Wear-resistant, High Hardness, Universal Size Details: Front Hub Ball Holder: Outer Diameter: 2cm/0.79", Steel Ball Diameter: 0.5cm/0.2" (Approx.) Rear Hub Ball Holder: Outer Diameter 2.5cm/0.98", Steel Ball Diameter: 0.6cm/0.24" (Approx.) Center Axis Ball Bracket: Outer Diameter 3cm/1.18", Steel Ball Diameter: 0.6cm/0.24" (Approx.) Rear Hub Ball Holder: Outer Diameter: 4cm/1.57" (Approx.) Notes: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Package Includes: 2 x Front Fork Headset Balls