As the bike headset features a sealed bearing, it guarantees a very smooth performance. And it is rustproof, corrosion-resistant, and impact-resistant.To your surprise, the bike headset is precisely machined to match the main tube of the frame. And it is comfortable to touch for a smooth surface and round corners.Made of aluminum alloy, it is durable.The size of the mounting caliber is 3.4cm, and the diameter is 2.86cm.It is suitable for being installed on the straight tube fork of a bicycleItem Name: Bike HeadsetMaterial: Aluminum AlloyFeatures: Threadless, Lightweight, Easy to InstallSize Details: Mounting Caliber: 3.4cm or 1.34" (Approx.)Inner Diameter: 2.86cm or 1.13" (Approx.)Height: 4.5cm or 1.77" (Approx.)Caliber: 3.4cm or 1.34" (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:1 Set of Bike Headset Note: 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.