The all-new 40-Series is the work-horse of Cane Creek's headset line-up. The series incorporates all the features necessary for a durable, light-weight, long-lasting headset and represents the perfect balance of performance, durability and value.Machined from 6061 T-6 AluminiumInnovative Clip-Seal completely seals the top assembly and captures the compression ring to reduce the numberof loose partsHigh quality, low friction face-sealsDurable steel crown raceDependable black oxide, sealed bearingsInterlock spacer compatibleUpper/Lower stack: 8/4mmColour: BlackWeight: 88gZS44/28.6|ZS44/30Zerostack 1.1/8" upper and lower