Are you talking about the "primer red" steel retaining wall in front of the image?
There are a few manufacturers, here's Faller and here's Greenway (not an nicely organized catalog, search for "Corten Steel Waterfront Pilings".There are others, and I know Model Railroader used some on a modern day Milwaukee project layout, but I can't remember which brand.
BTW, if it is the retaining walls, maybe change your thread title to indicate you're looking for the retaining walls shown in the flyer.