FSA Orbit Series Headset. Features: FSA's core line of headsets that have become an industry benchmark All Orbit headsets feature forged and CNC machined 6061 T6 alloy cups Orbit IS, CF, Z, ZS, X, MX, XL II include angular contact bearings Orbit Xtreme Pro include stainless steel industrial cartridge bearings and stainless crown race Orbit UF include lower angular contact bearing and upper 5/32" caged bearing Orbit DL include 5/32" caged bearings IS: 36x45 degree Cane Creek Integrated, CF: 45x45 degree Campagnolo Integrated, ZS: ZeroStack shallow, Z: ZeroStack deep, or Xtreme-Pro, X, MX, XLII, UF, DL: External Cup traditional available for 1", 1-1/8", tapered and 1.5" applications For clarification go to http://www.fsaeasyheadset.com Specs: Model:Orbit UF S H I S:EC34/28.6|EC34/30 Stack:15.3mm/13.4mm Color:black Weight:101g