From the Manufacturer

Trainline freight cars feature RP-25 metal wheels for superior performance on all kinds of Code 70 and larger HO Scale track. With their added weight and wheel tread matched to National Model Railroad Association standards, wheels on Trainline cars are perfect for every HO railroad. Other features include molded details that stand up to handling during operation, realistic paint schemes for good looks and body-mounted magnetic knuckle couplers for reliable performance.