Feature:1. The outer headset is made of aluminum alloy, made by T6 heat treatment and CNC process, with light weight and unchanged strength. Built in ditch ball bearing, efficient operation, lasting silence.2. Metal bearing 360 rotation, high accuracy, high speed, insert the fork accurately, unhindered and free.3. Integral sealed bearing, can effectively prolong the service life, the lubricant is retained in the bearing, dustproof and waterproof effect is good, suitable for harsh riding environment.4. Rubber waterproof circle, choose high quality rubber material, adding a layer of waterproof circle in the headset cover, anti corrosion, waterproof, silt prevention and durable.5. The bicycle headset is suitable for frame head tube with the inner diameter of the upper pipe 34mm / 1.3in, the inner diameter of the lower pipe 34mm / 1.3in, the outer diameter of the upper end of the front fork of the standard straight pipe is 28.6mm / 1.1in, and the outer diameter of the lower end is 30mm / 1.2in.Specification:Item Type: Bicycle Double Bearing HeadsetWeight: Approx.125g / 4.4ozMaterial: Aluminum AlloySpecifications: 34-34mm / 1.3-1.3in (With 28.6mm / 1.1in Straight Fork)Applicability: The Inner Diameter Of The Upper Tube Of Frame Head Tube Is 34mm / 1.3in And The Inner Diameter Of The Lower Tube Is 34mm / 1.3in. The Outer Diameter Of The Upper End Of The Front Fork Of The Standard Straight Pipe Is 28.6mm / 1.1in And The Outer Diameter Of The Lower End Is 30mm / 1.2in..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 List:1 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