Designed for oil-immersed de-energized voltage regulating transformers, this series of products comprises de-energized tap-changers. They feature a vertical cage structure and are installed in a bell type configuration. These tap-changers are suitable for use in power, rectifier, and electric furnace transformers with rated frequencies of 50Hz and 60Hz, rated voltages of 35kV, 66kV, and 110kV, and rated currents ranging from 125A to 2000A. It is important to ensure that the transformer is de-energized before operating these tap-changers.