The Hydro-Max is what we use for Ford and on up vehicles. It TVolve comes on many buses and tow trucks, along with almost anything built on a on up commercial chassis until air brakes come in. It works off the power steering pump as well, but instead of having an accumulator for backup, it has an electric motor that will continue to provide stopping power as long as there is a battery charge. This electric motor backup is an important feature because the vehicle won't come to any sort of safe stop if you had no power assist from the engine shutting off (like would happen with vacuum assist). The part numbers that International, GM, or another manufacturer can easily go obsolete if the vehicle is more than ten years old, because that is usually when the warranty support ends, we can retrofit new available units to fit whatever your application is. http://drozforskolin.org/tvolve-reviews/