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 ZS44/28.6|EC44/40 Black 28.6 44 40 20 36/45 1-1/8` - 1.5`