This is one of three parts parts that can be used to convert the 72' Bachmann N Scale coach to Southern Pacific suburban service coaches. The Bachmann coach windows need to be entirely removed and the window insert parts will fit into the long openening that remains.
These are sometimes called Harrimans but this is not exactly true. The Harrimans were shorter and had very different windows. To complete the conversion you need to use body putty to fill in the end windows.