Rockwill manufactures all kinds of step voltage regulators / AVR, like: oil immersed AVR, dry type AVR, ANSI / IEC standard type 32-Steps voltage regulators is oil immersed type,  Rockwill offer more options: single phase / three phase step voltage regulator, customized make type pad mounted step voltage regulator, substation type step voltage regulator, or distribution overhead line type, pole mount type step voltage regulators, etc.