Deutsche Bahn introduced two-car Desiro DMUs for local services in 2000. With a top speed of 120 km/h (75 mph), these Class 642 units are mainly used on branch lines and regional lines.

The Class 642 is equipped with two MTU diesel engines with an output of 315 kW (422 hp) each and hydro-mechanical transmission with retarders. It typically contains 100 seats. When linked together with Scharfenberg couplers, up to three trainsets can be operated together.