Cups and covers made of 7075 T-6 Aluminum, made in the USA 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 Dual-Seal crown race provides excellent seal efficiency with low friction Premium, sealed stainless-steel bearings Made In USA IS41/28.6|IS52/40 Black 28.6 41/52 40 10 1-1/8` - 1.5`UPC/EAN/GTIN: 840226117515