This Series represents intelligent digital actuators targeting the control method of the next generation. They are process control devices of multi-function hybrid structure incorporationg computer functions to fully utilize advan-tages of both electric and hydraulic types, ie., high speed and large output. Major components are digital motor, gear pump and electronic circuit. Unique hydraulic Flow Match System (pat-ented) controlled by direct digital signals secures stabilized high speed response and high accurancy action. Fail safe upon power loss. Furthermore, with three kinds of power modules that have redundancy and high power, electric safety is enhanced. With this Series, we have come closest ever to the concept of \"Maintenance free.\"