Feature:1. The outer headset is made of aluminum alloy, adopting T6 heat treatment, CNC technology, light weight and constant strength, built in ball bearings, efficient operation, long lasting silence.2. The metal bearing can rotate 360°, high accuracy, high speed, and accurately fit into the front fork, smoothly and freely.3. The headset adopts a colorful process, which is colored by water plating and vacuum plating. The hardness is strengthened, not easy to fade, and the appearance is higher.4. Equipped with double bearing structure, which is smoother and easier to maintain than loose ball bearings, and the turning of the handlebar is light and smooth.5. The integral sealed bearing keeps the lubricant in the bearing, has good dustproof and waterproof effect, prolongs the service life, and is suitable for harsh riding environment.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: Double Bearing HeadsetMaterial: Aluminum AlloySpecification: Approx. 44-50.6mm/1.7-2.0in (Use with 28.6 Straight Fork)Applicable Situation: Frame Head Tube: Upper Tube Inner Diameter 44mm/1.7in, Lower Tube Inner Diameter 50.6mm/2.0in. Front Fork: Upper End Outer Diameter 28.6mm/1.1in, Lower End Outer Diameter 30mm/1.2in.Applicable Measurement Instructions: (The Same Four Data Can