The series of products is a de-energized tap-changer for oil-immersed de-energized voltage regulating transformer, which adopts a vertical cage structure. It is installed in a bell type. It can be widely used in power, rectifier, electric furnace and other transformers with rated frequencies of 50Hz and 60Hz, rated voltages of 35kV, 66kV, 110 kV, and rated currents of 125A~2000A. It must be operated under the condition that the transformer is de-energized!