Description: 【High Precision Sealed Bearings】: Equipped with sealed deep groove ball bearings, this bike headset features metal sealed bearings that ensure high precision and high speed performance 【Universal for 44-52MM Frames】: This Bike Headset Bearing is compatible with frames having a head tube inner diameter of 44MM at the top and 52MM at the bottom, making it versatile for various mountain and road bikes 【Compatible Standard Forks】: Designed to fit standard straight forks with an upper outer diameter of 28.6MM and a lower outer diameter of 30MM, as well as standard tapered forks with an upper outer diameter of 28.6MM and a lower outer diameter of 39.8MM 【Construction】: Made from aluminum alloy, this Bicycle headset offers durability while maintaining a lightweight profile, ensuring long term performance on your bike 【Compact Dimensions】: With product dimensions of 6.2cmx6.2cmx5.5cm/2.44inchx2.44inchx2.17inch, this external headset is compact yet robust enough to provide reliable support for your bicycle's front fork assembly Specification: Material: Aluminum Alloy, Premium Bearings   Size Chart: 6.2cmx6.2cmx5.5cm/2.44inchx2.44inchx2.17inch Package Includes: 1 Bike Headset