For1-1/8 upper ,1.5" bottom steerer- For different outerdiameter head tube- 6061/T6 top cover with seals- 6061/T6 forged and cnc machined upper cup- 6061/T6 cold-forged and cne machined lower- Steel cne machined crown race (inner diameter 39. 8mm)- Upper: angular contact sealed bearing- Lower: super oversize angular contact sealed bearing- Size: 1.5" Head Tube Reduced to 1-1/8" Fork Tube Semi-Integrated Threadless Headset- Dimension:1-1/8"×44/50×56/62×39.8- ACB Sealed- Bearing: NHB-5D & NHB-15- Stack Height: 16.5+3=19.5mm 1mm- Weight: 135g (include Alloy top cap) - Color: Black (as pic. shown)- Made in TAIWANContent: 1 set (With top cap and starnut) / pack