The Aura Ceramic Metal Bearing is part of our new pinnacle bearing line developed for racers seeking the highest level of performance. We took what we learned from our rear ceramic engine bearings and shrank that technology down to offer the most advanced bearings for your RC vehicle. Considering the diversity of our loyal customers, spending more is not always the way to go. The Aura line is not designed for the warriors that race several times a week and don't have time to go through their car to provide the proper maintenance needed to keep the Aura in a good state. We recommend that you stick with our greased Halo Revolution bearing line which has established a prowess all of its own by being a 9-time IFMAR World Champion winning product.