FSA IS-2 UPPERAN UPPERCUTHeadsets can be a tricky thing to navigate. Many different bikes can use many different headset standards. The FSA IS-2 Upper is a replacement headset upper from FSA. It is designed to fit 1-1/8" upper headtubes and has a size of IS41.2/28.6. It uses cartridge bearings.FeaturesSize: 1-1/8" IS41.2/28.6 (36/45) 6.7/8.2mmReplacement headset upper from FSAManufacturer part number: 121-0520 | FSA Integrated Headset Upper IS-2 Black, 1-1/8 IS41.2/28.6 (36/45) 6.7/8.2mm