This is a Single 6x10x2.5mm Ceramic Bearing in case you need a spare or to replace a lost or damaged bearing.
Performance
Ceramic bearings are superior to steel bearings in may respects. Ceramic
bearings reduce rolling resistance by 50% and overall friction is reduced 22
fold over standard steel bearings. They also last 5-10 times longer than steel
bearings, making them a sound investment. They are stiffer which keeps your
wheels pointed dead and true, they spin faster for more top speed, accelerate
more rapidly for better performance off the line and have lower friction which
makes your driveline more efficient so batteries last longer and motors run
cooler.
Manufacturing
The entire manufacturing process can take as
much as 70 days. Ceramic bearing balls are made from Si3N4 silicon nitride that has been pressed under
extreme pressure, then sintered into incredibly hard pellets. To achieve the mirror fine finish the balls are magnetically levitated
and polished with a plasma beam. While all of this may sound pretty far out, it
is the reason why they cost so much.