Welcome to our store! 1. The integrated seal keeps the lubricant inside the bearing, ensuring a good seal against dust and water, extending its service life and making it suitable for harsh environments. 2. The outer cup is made of heat-treated T6 aluminum alloy and CNC machined, making it lightweight and durable. 3. Integrated deep groove ball bearing and metal bearing, high-speed, efficient, and quiet; by precisely inserting the fork, the bearing rotates smoothly 360°. 4. The high-quality waterproof rubber ring adds a protective layer to the cup cover, making it anti-corrosive, waterproof, and sediment-resistant, resulting in a longer service life. 5. Universal type for straight and tapered forks, suitable for standard tapered steerer tube forks with an upper outer diameter of 28.6 mm/1.12 inches and a lower outer diameter of 39.8 mm/1.6 inches, and standard straight steerer tube forks with an upper outer diameter of 28.6 mm/1.12 inches and a lower outer diameter of 30 mm/1.18 inches. Item Type: Bicycle Double Bearing Headset Material: Aluminum Alloy Application: For frame steerer tube: Upper tube inner diameter is 44 mm/1.7 inches and lower tube inner diameter is 55 mm/2.2 inches. For fork: Standard tapered tube fork, upper outer diameter 28.6 mm/1.12 inches, lower outer diameter 39.8 mm/1.6 inches; Standard straight tube fork, upper outer diameter 28.6 mm/1.12 inches, lower outer diameter 30 mm/1.18 inches. Weight: approx. 141 g/4.97 oz. Specifications: 44-55 mm/1.7-2.2 inches (universal type for straight and tapered forks). 1 x Sunflower Top Cap Set 1 x Headset Cap 1 x Pressure Ring 1 x Upper Bearing 1 x Upper Cup Set 1 x Lower Cup Set 1 x Lower Bearing 1 x 30 mm/1.18 inch Lower Derailleur 1 x 39.8 mm/1.6 inch Lower Derailleur Customers are our priority. If you find any problems with your product after receiving it, such as damage or an incorrect quantity, please contact us immediately. We strive to provide you with the best customer service.