{HEAD ~ A rotatable electrode} is inserted between these fixed electrodes, and this rotatable electrode is mounted on a shaft which is rotatably provided on {TAIL ~ the housing} 
{ HEAD ~ A rotatable electrode } is inserted between these fixed electrodes , and this rotatable electrode is mounted on a shaft which is rotatably provided on { TAIL ~ the housing }
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL