Iresa (Industrias Reunidas Españolas, SA) was the first company to start mass production of engines for bikes. Its monoblock "engine / gearbox" included a dry single plate clutch and a 2-speed gearbox. Each component beginning from the steering wheel to the carburetor was produced independently by Iresa. They were sold both ready-mopeds on the chassis Orbea, and special sets consisting of a motor and fuel tank, which were suitable for any moped.

The museum exhibits a moped with the engine on the chassis 48 Iresa BH.