Genuine OEM Kia Overdrive Clutch Balance Piston, part number 455423B000. This precision-engineered piston is a critical component within the transmission's overdrive clutch assembly. Its primary function is to help balance the clutch operation, ensuring smooth and efficient power transfer. Located internally within the transmission, it contributes to reliable gear engagement. Choosing a genuine OEM part ensures factory-specified tolerances and material composition, vital for the longevity and proper function of complex transmission systems.