The series is composed of an electric transmission mechanism, a switch body and an electric controller. It is suitable for oil-immersed transformers with a maximum equipment voltage of 126 kV or less, and a rated current of 1250A or less. Tap and switch in the de-energized state, which can be operated electrically or manually. It is used with our electric controller JLK-718A, and it can only be operated under the condition that the transformer is de-energized!