Feature:1. Outer bowl is made of aluminum alloy, T6 heat treatment, CNC technology, light weight, inbuilt full deep ditch ball bearing, efficient operation, lasting silence.2. Using metal bearings, 360° rotation, high accuracy, high speed, and accurate insertion of the front fork, unhindered and free.3. Integral sealed bearing keeps the lubricant in the bearing, dustproof and waterproof, prolongs the service life, suitable for harsh riding environments.4. Rubber 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.5. Suitable 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.How to Use:Product Order Description (From bottom to top, the headset is installed on the upper and lower ends of frame head tube): Bottom File‑Lower Bearing‑Lower Headset‑Upper Headset‑Upper Bearing‑Urgent Loop‑Headset Cover‑Sunflower Top Cover KitSpecification:Item 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)T