A headset designed to bridge the gap between the 40-series and 110-series headsets 6061 T-6 Aluminum, Internally contoured and relieved to minimize weight and maximize strength Low-friction upper bearing seal completely seals cup from contaminants and is fully captured by the top cover with no loose parts Alloy Dual-Seal crown race provides excellent seal efficiency with low friction Premium, sealed stainless-steel Hellbender bearings Bright, dip anodized Black finish IS42/28.6|IS52/40 Black 28.6 42/52 40 10 36/45 1-1/8` - 1.5`UPC/EAN/GTIN: 840226078564