Feature:1. Aluminum Alloy Material: Made of high quality aluminum alloy material, light weight, not easy to deform, and extend the service life.2. Steel Sunflower: Steel star nut is light in weight and has high strength, exquisite workmanship, beautiful appearance, long service life.3. Double Bearing Structure: The upper and lower double bearing structure of the headset is and unimpeded, labor saving and easy to protect.4. Rotate Freely: Bike headset can prevent the bearing from excessive wear and make it rotate freely. The lid is good for dust and water resistance to extend durability.5. Scope of Application: Ordinary cone tube fork and straight tube fork, 44mm/1.7in outer diameter of headset and 55mm/2.17in inner diameter of head tube.Specification:Item Type: HeadsetProduct Material: Aluminum Alloy + SteelWeight: Approx. 141g / 5.0ozHeadset Outer Diameter: Approx. 44mm / 1.7inHead Tube Inner Diameterr: Approx. 55mm / 2.17inApplication: Cone Tube Fork and Straight Tube Fork Package List:2 x Bearing1 x Star Nut Headset Cover Set 1 x Upper Urgent Loop1 x Upper Headset1 x Lower Headset1 x Bottom Cover1 x Top Cover1 x Reducing Sleeve