The Team Associated RC8B3 Factory Team Aluminum Pillow Balls are an optional upgrade for the standard steel pillow balls included with the RC8B3 and RC8B3e kits. Aluminum pillow balls reduce un-sprung mass in the front steering block assembly, resulting in a more aggressive steering feel. These are best suitded for smooth track conditions with high grip levels. Package includes two pillow balls. Two packages are required to convert one chassis.