Yeah Racing Hackmoto V2 Replacement Performance Motor Brushes. Motor brushes wear out over time resulting in decreased motor performance. Spraying out the motor with motor cleaner and installing new brushes can help maintain the performance of a brushed motor. Yeah Racing use a premium quality copper compound that is carefully formulated to achieve both great performance and durability. Additionally, the brushes are sintered for optimal performance and heat treated to improve lifespan. Package includes four brushes.