Robust CNC machined shell forged CNC machined shell that enhances durability while maintaining lightweight properties Silent operation with double bearings two sealed stainless steel bearings provide smooth and silent operation for a better riding experience Fit for head tube frames suitable for head tubes with a 6 mm outer diameter, compatible with most bikes on the market Ultralightweight design weighs approximately 120 g, making it an ideal choice for performancefocused cyclists seeking agility and speed Use scenarios Road performance upgrade reduces overall weight while preserving durability, improving acceleration and handling on paved climbs Daily commuting and endurance rides silent operation minimizes noise and wear, contributing to a smoother, more reliable ride over long distances Frame compatibility and upgrades convenient for builds and upgrades that use head tubes with a 6 mm outer diameter, enabling broad compatibility across many bikes