Wolf Tooth Performance Headset - EC49/40 Lower BlackWolf 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 to protect lower bearing in the toughest conditions Crown Race 40 Bearing Type Black Oxide Steel Color Black S. H. I. S Lower EC49