Feature:1. Premium Material: Adopting aluminium alloy material with T6 heat treatment and CNC technology, light weight and high hardness. Deep notch ball bearing ensures efficient operation and lasting silence.2. Metal Bearing: Adopting metal bearing with 360 degrees rotation, which ensures high accuracy, high revolving speed and stable performance.3. Dual Bearing Structure: Adopting dual bearing structure, easier and smoother to control handlebar. Integral sealing bearing can prolong service life and provide dustproof waterproof effect.4. Rubber Waterproof Ring: This bike bearing headset adopts premium rubber waterproof ring, which is corrosion resistant, waterproof and dustproof, longer service life.5. Reusable: This bike bearing headset is suitable for 28.6mm straight steerer fork, close and seamless installation, detachable and reusable.How to Use:From bottom to top:Lower bearingUpper bearingUrgent loopHeadset coverTop Cover KitSpecification:Item Type: Bike Bearing HeadsetMaterial: Aluminium Alloy and Stainless SteelSpecification: 41/49mm (Suitable for Direct Mounting of Bearing on Inner Diameter of Upper 41mm and Lower Inner Diameter of 49mm) Cone shaped Head Tube Frame + 28.6mm Caliber Straight Steerer Fork with Bottom Gear)Bearing Specifications: Upper Bearing φ41 x 6.5h x 45 Degrees, Lower Bearing φ49 x 7h x 45 Degrees Package List:1 xTop Cover Kit1 x Headset Cover1 x Headset Cover Loop1 x Urgent Loop1 x Upper Bearing 1 x Lower Bearing