This is one-half of a complete headset (the upper portion only). You would pair it with a seperate matching lower assembly sized to suit your frame/fork to have a complete headset. Integrated-style 41mm or 42mm for integrated (Campy-Style) headset top cups. Features high quality, black oxide sealed cartridge bearings "Short" has a stack height of 8mm and "Tall" has a stack height of 15mm Stuck? Dont guess - use the excellent Cane Creek Headset Fit Finder, or contact Jenson USA for guidance. | Cane Creek | 40 Is41/28. 6 Upper Headset | Black | Is41/28. 6 Short Cap 9Mm