This is the Athearn HO Scale Arch Roof Set, UP (3 Pack).

MODEL FEATURES:
Stirrup Steps
Separate Grab Irons
Window Glazing
Vestibule Partitions
Removable, magnetically attached roof
Weighted for optimum performance
McHenry® operating scale knuckle couplers
2 or 3-axle trucks, per prototype
Razor sharp paint and printing
Machined 33” metal RP25 profile wheels
RPO comes with mail hook details on both sides
Multi-pack includes: Combine, Diner, Observation Car
Car length: 8.5 inches
Minimum radius: 18”