Key benefits Smooth, quiet steering: builtin double stainless steel sealed bearings (imported) reduce friction and wear for consistent, lownoise rotation and responsive steering. Broad compatibility: fits tapered tube forks with a 28.6 mm outerdiameter upper tube (international standard) and head tubes 44–56 mm in diameter. Lightweight and durable: CNCforged aluminum alloy shell cuts weight (about 120 g total) while maintaining strength, heat resistance, and consistent fit. Easy maintenance and upgrade: designed for simple assembly and disassembly without special tools, allowing fast installation, routine maintenance, and hassle upgrades. What's included One sealed bearing headset set with: Upper pelling: 41 mm Upper bowl: 44 mm Lower bowl: 56 mm Lower pelling: 52 mm Bottom: 30 mm or 39.8 mm (two bottom size options) Total weight: 120 g Available anodized colors: black, red, blue, green, purple, gold Performance and construction Bearings: double stainless steel sealed bearings (imported) provide long service life, smooth rotation, and limited ingress of dirt and moisture. Shell: CNCforged aluminum alloy shell for precise dimensions and reliable compatibility across common road, mountain, and hybrid frames. Finish: anodized surface improves corrosion resistance and color retention under varied weather conditions. Compatibility and sizing Designed for head tubes 44–56 mm in diameter. Matches tapered forks with a 28.6 mm outerdiameter upper tube (international standard). Upper and lower cup / pelling dimensions listed above for exact fit checks. Suitable for frames that accept conical or straight tube forks. Installation and maintenance Toolfriendly design: engineered for simple assembly and disassembly without special tools; aligns directly into 44–56 mm head tubes for a secure fit. Optimized internal structure enables quick servicing of bearings and fast headset replacement when needed. Practical use scenarios 1. a worn headset on a commuter road bike to restore quiet, stable steering and reduce vibration through the handlebars. 2. Upgrade the headset on a mountain bike before a trail season to improve steering responsiveness and reduce bearing wear in wet or dusty conditions. 3. Fit a hybrid frame that uses a tapered fork and 28.6 mm upper tube to achieve lighter steering components and consistent alignment during routine maintenance. Specifications (concise) Application: tapered tube fork (28.6 mm OD upper tube) Head tube compatibility: 44–56 mm Components: upper pelling (41 mm), upper bowl (44 mm), lower bowl (56 mm), lower pelling (52 mm), bottom (30 or 39.8 mm) Bearings: double stainless steel sealed bearings (imported) Material: CNCforged aluminum alloy shell Finish: anodized (black, red, blue, green, purple, gold) Weight: approximately 120 g If you need to verify fit for a specific frame or fork model, check your head tube inner diameter and fork upper tube outer diameter against the dimensions listed above.