9 Passenger Car Tire-Balancing Machines, Manual, Air-Lock, and Conveyorized Air-Lock Passenger Car-Tire Balancing Machines, Passenger Car Automatic Tire-Balancing Machines, Truck Tire-Balancing Machines, Automatic Truck Tire-Balancing Machines, Aircraft and Heavy-Duty Truck Tire-Balancing Machines, and Aircraft Tire-Balancing Machines, and Structural Component Parts Thereof, Machines for Balancing Helicopter Main Rotor Blades and Structural Component Parts of Such Machines