Big Airbox Kit - YamahaCaracteristicas: In cooperation with several Yamaha teams and riders Twin Air has developed a new Airbox Kit for the Yamaha YZ250F 450F Kit creates more open space within the airbox to optimize the airflow into the engine The bigger airbox then allows for a bigger Air Filter on the Twin Air Powerflow Kit Kit includes a Big Air Filter, black Airbox Lid, aluminum cage and sealing ring, air filter bolt, spacer and mounting hardware Easy to install