The O&K RH9 was first sold in the late sixties. At that time it weighed 21 metric tons ( lb) and was powered by a 120 hp Deutz engine. It was built under the same name until the late nineties, but was modified in various aspects over time.

The real machines as well as the Conrad models also saw a variety of painting schemes during their production time. This model ist the fourth edition made by Conrad.