1-3/8_ Angular Contact Bearing for Internal Headset featuring anti-corrosion Black Oxide/Magnetite coating of 52100 High-Carbon Chromium alloy races paired with grade 10 Balls. The Enduro line of headset bearings begin with chromium steel, Black Oxide finish A/C type and then offer full 440C stainless steel at the top. They are always engineered with the largest balls possible and dual lip seals riding in a micro groove for ultimate protection against sweat and the elements. They are filled 90% with high pressure waterproof grease, so you never have to guess if there is grease inside. In Angular Contact (A/C) bearings, ALL balls are engaged and spread the force over a larger surface area, to decrease friction and minimize wear. Bearing Code: 6806 CC BO Dimensions: 37 x 49 x 6.5mm ABEC: 3 Grade: 10 Seals: LLB Grease: Kyodo Yushi PS-2 Application: Headsets Weight: 25.25g