Emerson made this unit for accommodating low torque applications below 90ft-lbs. This is useful for boilers, butterfly valves, fired heaters and jackshafts among other units and has a 4x5 cylinder for when 180ft-lbs of torque is needed.
Perfect for many controls for process valves, feed units, dampers and other items that come around when the demand signal gets in the way, it works in many applications.