From the Manufacturer

Just couple this car into your train and start cleaning. Cleans tracks for better performance while you run your trains. Soft-abrasive pad mounted under car wipes away grime without scratching rail surfaces. 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.