Avid Ceramic & steel engine bearings
Avid have released ceramic & steel engine bearings, which offer the maximum performance and reliability to your racing engine at an unbeatable price. The bearing specs are Abec5, G3 Si3N4 ceramic balls, PA66 with 30 glass fiber cage, and chrome steel 52100 rings and it has no seals to allow for proper lubrication from the oil in your fuel. A ceramic engine bearing can allow most RC engines to spin an extra 500 rpm with less drag and the life of the bearing is far greater over a steel bearing. Another benefit to ceramics is the weight difference in the balls allowing for less rotating mass.
Source: Avid [avidrc.com]