Wolf Tooth Performance Headset - ZS56/40 Lower, OrangeWolf Tooth Performance Headsets are machined out of aircraft grade aluminum and assembled with Black Oxide Cartridge Bearings, balancing quality and price. Black Oxide Bearings are made from chromium steel for high load capacity and durability Custom molded dual lip seal on the crown race protects lower bearing in the toughest conditions Item Specifications Bearing Type Black Oxide Steel Bearing Type Cartridge Color Orange Crown Race 40 S. H. I. S