It was the old model turbo on the large bore Cummins engines. Dates back to the late 60's. It was built by Cummins. The later model Cummins use Holset turbos. Holset was a British Co. ,which was bought out by Cummins in the 80's and is a subsidery of the Cummins Engine co. The Holset turbos were built on a Schwitzer design and patent license agreement.