National Steel Car plastic pellet hoppers are built especially for hauling pelletized plastic from manufacturers to molding plants. As with similar lightweight materials, bigger cars are used to carry a maximum payload, and hoppers like this can be found at producing and consuming industries. Details on these ready-to-run cars include separate roofwalks, pneumatic piping, control valves, brake cylinders, brake wheel, air reservoir and hatches, modeler-applied wire grab irons. The cars come equipped with RP-25 metal wheels and Proto MAX(TM) metal knuckle couplers.