?Item Type: Bike Headset Spacer Set _x000D_ Material: Aluminium Alloy _x000D_ Inner Diameter: Approx. 28.6mm / 1.1in_x000D_ External Diameter: Approx. 34.0mm/ 1.3in_x000D_ Thickness: _x000D_ 2mm / 0.1in_x000D_ 3mm / 0.1in_x000D_ 5mm / 0.2in_x000D_ 10mm / 0.4in_x000D_ Product Weight: Approx. 29g / 1.0oz_x000D_ Compatibility: Suitable for fork tubes with a diameter of 28.6mm / 1.1in 1Using high?quality aluminum alloy material, it is environmentally friendly, strong and durable. 2Light in weight and easy to install, it has the advantages of smooth surface and exquisite workmanship. 3The spacer is a necessary component for loading, and its function is to lock the front assembly with a suitable spacer height. 4There are 4 different sizes (2mm/3mm/5mm/10mm), you can adjust the appropriate height according to your own situation. 5The headset spacer is perfectly suitable for 28.6mm/1.1in front stem fork of mountain bike, road bike etc.6 x Spacer