DT/Swiss 240 Standard ZERO ceramic bearing kit.
The ZERØ ceramic bearings have ceramic balls and steel races. The balls are Grade 3, Silicon Nitride (Si3n4). These are the roundest balls you can buy without a military license. The races are treated with a black oxide coating, which helps prevent rusting in the bearing. The races are then reground to a mirror finish after this treatment. Finally, they are cryogenically treated for strength before assembly. We also use Silicone VV seals, which is the lightest drag seal available on the market.