Features1Aluminum Alloy Material: Made of high quality aluminum alloy material, light weight, not easy to deform, and extend the service life. 2Steel Sunflower: Steel star nut is light in weight and has high strength, exquisite workmanship, beautiful appearance, long service life. 3Double Bearing Structure: The upper and lower double bearing structure of the headset is smooth and unimpeded, labor saving and easy to protect. 4Rotate 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. 5Scope 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.SpecificationItem Type: Bicycle 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 ForkPackage List2 x Bearing1 x Star Nut Headset Cover Set1 x Upper Urgent Loop1 x Upper Headset1 x Lower Headset1 x Bottom Cover1 x Top Cover1 x Reducing Sleeve