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. Features of these models include: One time run of these roadnumbers, order now - limited quantity available In service from late 1990s to the present Built especially for heavier materials including fracking sand, cement, bentonite and more Separately applied brake gear, running board, discharge gates, inlet hatches and end ladder cages Correct 36′ RP-25 metal wheelsets Proto MAX(TM) metal knuckle couplers See the complete selection here!