WalthersMainline makes it easy to add more business to your HO Scale railroad with the 39' Trinity 3281 2-Bay Covered Hoppers! Built especially to handle heavier materials, they're often seen in unit trains moving loads of fracturing sand to new oil fields. Based on the later production prototypes introduced in the 1990s with seven side panels (two narrow and five large), they can also be found moving cement, bentonite and other heavier cargoes. Ready for service in a variety of modern schemes, each with four numbers, they're perfect for serving the Cornerstone(R) Glacier Industrial Sands (933-4035), or the Road-to-Rail Aggregate Transfer (933-4036) structure kits, both sold separately.