To carry upto 7 sieves of 8" dia it is driven by 1/4 HP electric motor, through reduction gear. The sieve table doesn't rotate but is inclined from the vertical axis the direction. In addition to the gyratory motion of the table, there is an upward and downward movement ensuring that each square inch of the sieve is utilised. To works on on 220/230 Volts single phase AC. Supplied complete with adaptor for 8" sieves but without test sieves.