Are available in a full range obtainable from the producer with regards to the accessories serving for assembly or adjusting operations. Depending on the type servo-motors are available from 2 Nm to 15 Nm of capacity for throttling valves with large intersections. The simplest variants possess only an open/close function, however it is possible to deliver types with the potential of analog control or with the option of utilizing the three extreme positions of the servo-motor. It is also possible to get a servo-motor with a reversible spring, which in the case of electric voltage fade causes the opening or closing of the throttling valve.