FSAs core line of headsets that have become an industry benchmark\nAll 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 inch caged bearing
Orbit DL include 5/32 inch 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 inch, 1-1/8 inch, tapered and 1.5 inch applications
For clarification go to http://www.fsaeasyheadset.com