Features1Outer bowl is made of aluminum alloy, T6 heat treatment, CNC technology, light weight, inbuilt full deep ditch ball bearing, efficient operation, lasting silence. 2Using metal bearings, 360 Degree rotation, high accuracy, high speed, and accurate insertion of the front fork, unhindered and free. 3Integral sealed bearing keeps the lubricant in the bearing, dustproof and waterproof, prolongs the service life, suitable for harsh riding environments. 4Rubber waterproof loop is made of high quality rubber, and a layer of waterproof loop is added to the bowl cover, which is anticorrosive and has a longer service life. 5Suitable for the inner diameter of the upper tube of frame head tube is 44mm and the inner diameter of the lower tube is 44mm. The standard cone tube fork , the outer diameter of the upper end is 28.6mm and the outer diameter of the lower end is 39.8mm.SpecificationItem Type: Bike HeadsetMaterial: Aluminum AlloySpecification: 44-44mm (Use with 1.5 Cone Fork)Applicable Situation: Frame Head Tube: Upper Tube Inner Diameter 44mm, Lower Tube Inner Diameter 44mm. Front Fork: Upper End Outer Diameter 28.6mm, Lower End Outer Diameter 39.8mm.Applicable Measurement Instructions: (The same four data can be applied)The inner diameter of the upper tube and the inner diameter of the lower tube, to obtain the inner diameter of the upper and lower tubes of frame;The outer diameter of the upper end and the outer diameter of the lower end are the outer diameters of the upper and lower ends of the front fork.Package List1 x Sunflower Top Cover Kit1 x Headset Cover1 x Urgent Loop1 x Upper Bearing1 x Upper Headset1 x Lower Headset1 x Lower Bearing1 x Bottom File