This H.O. Scale TrinityRail 3281 Cu.Ft. 2-Bay Covered Hopper is based on a common late-1990s and later prototype commonly used to haul frac sand, roofing granules and similar materials. With the boom in frack sand traffic it isn't uncommon to see these prototypes used in unit trains. Prototype cars measure 41'-11" long, and the cars are equipped with three or five round loading hatches and a pair of gravity outlets for commodity off-loading. Compared with earlier 2-bay covered hoppers, these cars are distinctive. Notably, an overhanging arched roof, heavy top reinforcement stiffener, and folded jack pads at the bolster are spotting features for the Trinity 3281. This design has proven to be popular with shippers and railroads alike.

The HO scale freight car features an injection-molded body, applied wire grab irons, photo-etched walkways and working shelf-type knuckle couplers without trip pins for scale appearance. Other details include roadnumbers printed on the truck sideframes, coupler cut levers, NMRA compliant car weight, trucks with spinning bearing caps, multiple roadnumbers per scheme and graffiti on select roadnumbers.