This detailed, ready-to-run HO Scale Trinity 3230 Pressure Differential 3-Bay Covered Hopper is essentially a smaller version of TrinityRail's 5660 PD. Developed from the base design introduced by Thrall Car in the late 1990s, its smaller size enables the car to be loaded with heavier commodities like cement and various grades of fly ash. Most of the cars are operated by leasing companies or shippers. The TrinityRail 3230 features a detailed, injection-molded body, appropriate trucks with metal wheels, body-mounted AccuMate knuckle couplers and accurate decoration. The Trinity 3230 Pressure Differential 3-Bay Covered Hopper is one of many Atlas and Trainman HO Scale covered hoppers.