Features： 1、Aluminum Alloy Material: Bicycle bearing headset is made of high quality aluminum alloy material, light weight, not easy to deform, and extend the service life. 2、Steel Star Nut Part: Steel star nut part 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 smooth 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 56mm/2.20in inner diameter of head tube. Specification： Item Type: Bicycle Headset Product Material: Aluminum Alloy + Steel Product Color: Blue Weight: Approx. 138g / 4.9oz Headset Outer Diameter: Approx. 44mm / 1.7in Head Tube Inner Diameterr: Approx. 56mm / 2.20in Application: Cone Tube Fork and Straight Tube Fork Package List： 2 x Bearing 1 x Star Nut Headset Cover Set  1 x Upper Pressing Loop 1 x Upper Headset 1 x Lower Headset 1 x Bottom Cover 1 x Top Cover 1 x Reducing Sleeve